Contract Source Code:

// SPDX-License-Identifier: MIT
pragma solidity 0.8.26;

import {ERC20} from "solmate/tokens/ERC20.sol";
import {OwnableRoles} from "solady/auth/OwnableRoles.sol";

/**
 * @title NektarToken
 * @notice Implementation of the Nektar Token with transfer restrictions and whitelist functionality
 * @dev Extends ERC20 and OwnableRoles to provide a token with time-based transfer restrictions and whitelisting
 */
contract NektarToken is ERC20, OwnableRoles {
    /**
     * @notice The role for addresses that are allowed to transfer tokens before the timelock expires
     * @dev Uses the first available role from OwnableRoles
     */
    uint256 internal constant _TRANSFER_ROLE = _ROLE_0;

    /**
     * @notice The timestamp after which all transfers are allowed
     * @dev Set during contract deployment and cannot be changed afterwards
     */
    bool public isTransferable;

    /**
     * @notice Error thrown when a transfer is attempted before the timelock expires by a non-whitelisted address
     */
    error TransferNotAllowed();

    /**
     * @notice Error thrown when an invalid address is provided
     */
    error InvalidAddress();

    /**
     * @notice Error thrown when transferability is already enabled
     */
    error TransferabilityAlreadyEnabled();

    /**
     * @notice Event emitted when transferability is enabled
     */
    event TransferabilityEnabled();

    /**
     * @notice Initializes the NektarToken contract
     * @dev Sets up the token with initial supply, transfer timelock, and whitelist
     * @param _transferWhitelist Array of addresses initially whitelisted for transfers
     * @param _owner The address to receive the initial token supply, allowed to make the distribution and enable transferability
     */
    constructor(
        address[] memory _transferWhitelist,
        address _owner
    ) ERC20("Nektar Token", "NET", 18) {
        _mint(_owner, 1_000_000_000 ether);

        _initializeOwner(_owner);

        for (uint256 i; i < _transferWhitelist.length; i++) {
            _grantRoles(_transferWhitelist[i], _TRANSFER_ROLE);
        }
    }

    /**
     * @notice Transfers tokens to a specified address
     * @dev Overrides ERC20 transfer function to include transfer restrictions
     * @param to The address to transfer tokens to
     * @param amount The amount of tokens to transfer
     * @return bool Returns true if the transfer was successful
     */
    function transfer(
        address to,
        uint256 amount
    ) public override returns (bool) {
        _onlyTransferable();
        return super.transfer(to, amount);
    }

    /**
     * @notice Transfers tokens from one address to another
     * @dev Overrides ERC20 transferFrom function to include transfer restrictions
     * @param from The address to transfer tokens from
     * @param to The address to transfer tokens to
     * @param amount The amount of tokens to transfer
     * @return bool Returns true if the transfer was successful
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public override returns (bool) {
        _onlyTransferable();
        return super.transferFrom(from, to, amount);
    }

    /**
     * @notice Grants the specified address the ability to transfer tokens before the timelock expires
     * @param _address The address to grant the transfer role
     */
    function grantTransferRole(address _address) external onlyOwner {
        if (_address == address(0)) {
            revert InvalidAddress();
        }

        _grantRoles(_address, _TRANSFER_ROLE);
    }

    /**
     * @notice Enables token transferability for all holders
     * @dev Can only be called by the contract owner. Once enabled, cannot be disabled.
     * @dev Reverts with TransferabilityAlreadyEnabled if transferability is already enabled
     * @custom:emits TransferabilityEnabled when transferability is successfully enabled
     */
    function enableTransferability() external onlyOwner {
        if (isTransferable) {
            revert TransferabilityAlreadyEnabled();
        }

        isTransferable = true;

        emit TransferabilityEnabled();
    }

    /**
     * @notice Checks if the caller is allowed to transfer tokens
     * @dev Reverts if the transfer is not allowed based on timelock and whitelist status
     */
    function _onlyTransferable() internal view {
        if (isTransferable) {
            return;
        }

        if (msg.sender == owner()) return;

        if (hasAnyRole(msg.sender, _TRANSFER_ROLE)) {
            return;
        }

        revert TransferNotAllowed();
    }
}

// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity >=0.8.0;

/// @notice Modern and gas efficient ERC20 + EIP-2612 implementation.
/// @author Solmate (https://github.com/transmissions11/solmate/blob/main/src/tokens/ERC20.sol)
/// @author Modified from Uniswap (https://github.com/Uniswap/uniswap-v2-core/blob/master/contracts/UniswapV2ERC20.sol)
/// @dev Do not manually set balances without updating totalSupply, as the sum of all user balances must not exceed it.
abstract contract ERC20 {
    /*//////////////////////////////////////////////////////////////
                                 EVENTS
    //////////////////////////////////////////////////////////////*/

    event Transfer(address indexed from, address indexed to, uint256 amount);

    event Approval(address indexed owner, address indexed spender, uint256 amount);

    /*//////////////////////////////////////////////////////////////
                            METADATA STORAGE
    //////////////////////////////////////////////////////////////*/

    string public name;

    string public symbol;

    uint8 public immutable decimals;

    /*//////////////////////////////////////////////////////////////
                              ERC20 STORAGE
    //////////////////////////////////////////////////////////////*/

    uint256 public totalSupply;

    mapping(address => uint256) public balanceOf;

    mapping(address => mapping(address => uint256)) public allowance;

    /*//////////////////////////////////////////////////////////////
                            EIP-2612 STORAGE
    //////////////////////////////////////////////////////////////*/

    uint256 internal immutable INITIAL_CHAIN_ID;

    bytes32 internal immutable INITIAL_DOMAIN_SEPARATOR;

    mapping(address => uint256) public nonces;

    /*//////////////////////////////////////////////////////////////
                               CONSTRUCTOR
    //////////////////////////////////////////////////////////////*/

    constructor(
        string memory _name,
        string memory _symbol,
        uint8 _decimals
    ) {
        name = _name;
        symbol = _symbol;
        decimals = _decimals;

        INITIAL_CHAIN_ID = block.chainid;
        INITIAL_DOMAIN_SEPARATOR = computeDomainSeparator();
    }

    /*//////////////////////////////////////////////////////////////
                               ERC20 LOGIC
    //////////////////////////////////////////////////////////////*/

    function approve(address spender, uint256 amount) public virtual returns (bool) {
        allowance[msg.sender][spender] = amount;

        emit Approval(msg.sender, spender, amount);

        return true;
    }

    function transfer(address to, uint256 amount) public virtual returns (bool) {
        balanceOf[msg.sender] -= amount;

        // Cannot overflow because the sum of all user
        // balances can't exceed the max uint256 value.
        unchecked {
            balanceOf[to] += amount;
        }

        emit Transfer(msg.sender, to, amount);

        return true;
    }

    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public virtual returns (bool) {
        uint256 allowed = allowance[from][msg.sender]; // Saves gas for limited approvals.

        if (allowed != type(uint256).max) allowance[from][msg.sender] = allowed - amount;

        balanceOf[from] -= amount;

        // Cannot overflow because the sum of all user
        // balances can't exceed the max uint256 value.
        unchecked {
            balanceOf[to] += amount;
        }

        emit Transfer(from, to, amount);

        return true;
    }

    /*//////////////////////////////////////////////////////////////
                             EIP-2612 LOGIC
    //////////////////////////////////////////////////////////////*/

    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) public virtual {
        require(deadline >= block.timestamp, "PERMIT_DEADLINE_EXPIRED");

        // Unchecked because the only math done is incrementing
        // the owner's nonce which cannot realistically overflow.
        unchecked {
            address recoveredAddress = ecrecover(
                keccak256(
                    abi.encodePacked(
                        "\x19\x01",
                        DOMAIN_SEPARATOR(),
                        keccak256(
                            abi.encode(
                                keccak256(
                                    "Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)"
                                ),
                                owner,
                                spender,
                                value,
                                nonces[owner]++,
                                deadline
                            )
                        )
                    )
                ),
                v,
                r,
                s
            );

            require(recoveredAddress != address(0) && recoveredAddress == owner, "INVALID_SIGNER");

            allowance[recoveredAddress][spender] = value;
        }

        emit Approval(owner, spender, value);
    }

    function DOMAIN_SEPARATOR() public view virtual returns (bytes32) {
        return block.chainid == INITIAL_CHAIN_ID ? INITIAL_DOMAIN_SEPARATOR : computeDomainSeparator();
    }

    function computeDomainSeparator() internal view virtual returns (bytes32) {
        return
            keccak256(
                abi.encode(
                    keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"),
                    keccak256(bytes(name)),
                    keccak256("1"),
                    block.chainid,
                    address(this)
                )
            );
    }

    /*//////////////////////////////////////////////////////////////
                        INTERNAL MINT/BURN LOGIC
    //////////////////////////////////////////////////////////////*/

    function _mint(address to, uint256 amount) internal virtual {
        totalSupply += amount;

        // Cannot overflow because the sum of all user
        // balances can't exceed the max uint256 value.
        unchecked {
            balanceOf[to] += amount;
        }

        emit Transfer(address(0), to, amount);
    }

    function _burn(address from, uint256 amount) internal virtual {
        balanceOf[from] -= amount;

        // Cannot underflow because a user's balance
        // will never be larger than the total supply.
        unchecked {
            totalSupply -= amount;
        }

        emit Transfer(from, address(0), amount);
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

import {Ownable} from "./Ownable.sol";

/// @notice Simple single owner and multiroles authorization mixin.
/// @author Solady (https://github.com/vectorized/solady/blob/main/src/auth/Ownable.sol)
/// @dev While the ownable portion follows [EIP-173](https://eips.ethereum.org/EIPS/eip-173)
/// for compatibility, the nomenclature for the 2-step ownership handover and roles
/// may be unique to this codebase.
abstract contract OwnableRoles is Ownable {
    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                           EVENTS                           */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev The `user`'s roles is updated to `roles`.
    /// Each bit of `roles` represents whether the role is set.
    event RolesUpdated(address indexed user, uint256 indexed roles);

    /// @dev `keccak256(bytes("RolesUpdated(address,uint256)"))`.
    uint256 private constant _ROLES_UPDATED_EVENT_SIGNATURE =
        0x715ad5ce61fc9595c7b415289d59cf203f23a94fa06f04af7e489a0a76e1fe26;

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                          STORAGE                           */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev The role slot of `user` is given by:
    /// ```
    ///     mstore(0x00, or(shl(96, user), _ROLE_SLOT_SEED))
    ///     let roleSlot := keccak256(0x00, 0x20)
    /// ```
    /// This automatically ignores the upper bits of the `user` in case
    /// they are not clean, as well as keep the `keccak256` under 32-bytes.
    ///
    /// Note: This is equivalent to `uint32(bytes4(keccak256("_OWNER_SLOT_NOT")))`.
    uint256 private constant _ROLE_SLOT_SEED = 0x8b78c6d8;

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                     INTERNAL FUNCTIONS                     */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Overwrite the roles directly without authorization guard.
    function _setRoles(address user, uint256 roles) internal virtual {
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x0c, _ROLE_SLOT_SEED)
            mstore(0x00, user)
            // Store the new value.
            sstore(keccak256(0x0c, 0x20), roles)
            // Emit the {RolesUpdated} event.
            log3(0, 0, _ROLES_UPDATED_EVENT_SIGNATURE, shr(96, mload(0x0c)), roles)
        }
    }

    /// @dev Updates the roles directly without authorization guard.
    /// If `on` is true, each set bit of `roles` will be turned on,
    /// otherwise, each set bit of `roles` will be turned off.
    function _updateRoles(address user, uint256 roles, bool on) internal virtual {
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x0c, _ROLE_SLOT_SEED)
            mstore(0x00, user)
            let roleSlot := keccak256(0x0c, 0x20)
            // Load the current value.
            let current := sload(roleSlot)
            // Compute the updated roles if `on` is true.
            let updated := or(current, roles)
            // Compute the updated roles if `on` is false.
            // Use `and` to compute the intersection of `current` and `roles`,
            // `xor` it with `current` to flip the bits in the intersection.
            if iszero(on) { updated := xor(current, and(current, roles)) }
            // Then, store the new value.
            sstore(roleSlot, updated)
            // Emit the {RolesUpdated} event.
            log3(0, 0, _ROLES_UPDATED_EVENT_SIGNATURE, shr(96, mload(0x0c)), updated)
        }
    }

    /// @dev Grants the roles directly without authorization guard.
    /// Each bit of `roles` represents the role to turn on.
    function _grantRoles(address user, uint256 roles) internal virtual {
        _updateRoles(user, roles, true);
    }

    /// @dev Removes the roles directly without authorization guard.
    /// Each bit of `roles` represents the role to turn off.
    function _removeRoles(address user, uint256 roles) internal virtual {
        _updateRoles(user, roles, false);
    }

    /// @dev Throws if the sender does not have any of the `roles`.
    function _checkRoles(uint256 roles) internal view virtual {
        /// @solidity memory-safe-assembly
        assembly {
            // Compute the role slot.
            mstore(0x0c, _ROLE_SLOT_SEED)
            mstore(0x00, caller())
            // Load the stored value, and if the `and` intersection
            // of the value and `roles` is zero, revert.
            if iszero(and(sload(keccak256(0x0c, 0x20)), roles)) {
                mstore(0x00, 0x82b42900) // `Unauthorized()`.
                revert(0x1c, 0x04)
            }
        }
    }

    /// @dev Throws if the sender is not the owner,
    /// and does not have any of the `roles`.
    /// Checks for ownership first, then lazily checks for roles.
    function _checkOwnerOrRoles(uint256 roles) internal view virtual {
        /// @solidity memory-safe-assembly
        assembly {
            // If the caller is not the stored owner.
            // Note: `_ROLE_SLOT_SEED` is equal to `_OWNER_SLOT_NOT`.
            if iszero(eq(caller(), sload(not(_ROLE_SLOT_SEED)))) {
                // Compute the role slot.
                mstore(0x0c, _ROLE_SLOT_SEED)
                mstore(0x00, caller())
                // Load the stored value, and if the `and` intersection
                // of the value and `roles` is zero, revert.
                if iszero(and(sload(keccak256(0x0c, 0x20)), roles)) {
                    mstore(0x00, 0x82b42900) // `Unauthorized()`.
                    revert(0x1c, 0x04)
                }
            }
        }
    }

    /// @dev Throws if the sender does not have any of the `roles`,
    /// and is not the owner.
    /// Checks for roles first, then lazily checks for ownership.
    function _checkRolesOrOwner(uint256 roles) internal view virtual {
        /// @solidity memory-safe-assembly
        assembly {
            // Compute the role slot.
            mstore(0x0c, _ROLE_SLOT_SEED)
            mstore(0x00, caller())
            // Load the stored value, and if the `and` intersection
            // of the value and `roles` is zero, revert.
            if iszero(and(sload(keccak256(0x0c, 0x20)), roles)) {
                // If the caller is not the stored owner.
                // Note: `_ROLE_SLOT_SEED` is equal to `_OWNER_SLOT_NOT`.
                if iszero(eq(caller(), sload(not(_ROLE_SLOT_SEED)))) {
                    mstore(0x00, 0x82b42900) // `Unauthorized()`.
                    revert(0x1c, 0x04)
                }
            }
        }
    }

    /// @dev Convenience function to return a `roles` bitmap from an array of `ordinals`.
    /// This is meant for frontends like Etherscan, and is therefore not fully optimized.
    /// Not recommended to be called on-chain.
    /// Made internal to conserve bytecode. Wrap it in a public function if needed.
    function _rolesFromOrdinals(uint8[] memory ordinals) internal pure returns (uint256 roles) {
        /// @solidity memory-safe-assembly
        assembly {
            for { let i := shl(5, mload(ordinals)) } i { i := sub(i, 0x20) } {
                // We don't need to mask the values of `ordinals`, as Solidity
                // cleans dirty upper bits when storing variables into memory.
                roles := or(shl(mload(add(ordinals, i)), 1), roles)
            }
        }
    }

    /// @dev Convenience function to return an array of `ordinals` from the `roles` bitmap.
    /// This is meant for frontends like Etherscan, and is therefore not fully optimized.
    /// Not recommended to be called on-chain.
    /// Made internal to conserve bytecode. Wrap it in a public function if needed.
    function _ordinalsFromRoles(uint256 roles) internal pure returns (uint8[] memory ordinals) {
        /// @solidity memory-safe-assembly
        assembly {
            // Grab the pointer to the free memory.
            ordinals := mload(0x40)
            let ptr := add(ordinals, 0x20)
            let o := 0
            // The absence of lookup tables, De Bruijn, etc., here is intentional for
            // smaller bytecode, as this function is not meant to be called on-chain.
            for { let t := roles } 1 {} {
                mstore(ptr, o)
                // `shr` 5 is equivalent to multiplying by 0x20.
                // Push back into the ordinals array if the bit is set.
                ptr := add(ptr, shl(5, and(t, 1)))
                o := add(o, 1)
                t := shr(o, roles)
                if iszero(t) { break }
            }
            // Store the length of `ordinals`.
            mstore(ordinals, shr(5, sub(ptr, add(ordinals, 0x20))))
            // Allocate the memory.
            mstore(0x40, ptr)
        }
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                  PUBLIC UPDATE FUNCTIONS                   */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Allows the owner to grant `user` `roles`.
    /// If the `user` already has a role, then it will be an no-op for the role.
    function grantRoles(address user, uint256 roles) public payable virtual onlyOwner {
        _grantRoles(user, roles);
    }

    /// @dev Allows the owner to remove `user` `roles`.
    /// If the `user` does not have a role, then it will be an no-op for the role.
    function revokeRoles(address user, uint256 roles) public payable virtual onlyOwner {
        _removeRoles(user, roles);
    }

    /// @dev Allow the caller to remove their own roles.
    /// If the caller does not have a role, then it will be an no-op for the role.
    function renounceRoles(uint256 roles) public payable virtual {
        _removeRoles(msg.sender, roles);
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                   PUBLIC READ FUNCTIONS                    */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Returns the roles of `user`.
    function rolesOf(address user) public view virtual returns (uint256 roles) {
        /// @solidity memory-safe-assembly
        assembly {
            // Compute the role slot.
            mstore(0x0c, _ROLE_SLOT_SEED)
            mstore(0x00, user)
            // Load the stored value.
            roles := sload(keccak256(0x0c, 0x20))
        }
    }

    /// @dev Returns whether `user` has any of `roles`.
    function hasAnyRole(address user, uint256 roles) public view virtual returns (bool) {
        return rolesOf(user) & roles != 0;
    }

    /// @dev Returns whether `user` has all of `roles`.
    function hasAllRoles(address user, uint256 roles) public view virtual returns (bool) {
        return rolesOf(user) & roles == roles;
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                         MODIFIERS                          */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Marks a function as only callable by an account with `roles`.
    modifier onlyRoles(uint256 roles) virtual {
        _checkRoles(roles);
        _;
    }

    /// @dev Marks a function as only callable by the owner or by an account
    /// with `roles`. Checks for ownership first, then lazily checks for roles.
    modifier onlyOwnerOrRoles(uint256 roles) virtual {
        _checkOwnerOrRoles(roles);
        _;
    }

    /// @dev Marks a function as only callable by an account with `roles`
    /// or the owner. Checks for roles first, then lazily checks for ownership.
    modifier onlyRolesOrOwner(uint256 roles) virtual {
        _checkRolesOrOwner(roles);
        _;
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                       ROLE CONSTANTS                       */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    // IYKYK

    uint256 internal constant _ROLE_0 = 1 << 0;
    uint256 internal constant _ROLE_1 = 1 << 1;
    uint256 internal constant _ROLE_2 = 1 << 2;
    uint256 internal constant _ROLE_3 = 1 << 3;
    uint256 internal constant _ROLE_4 = 1 << 4;
    uint256 internal constant _ROLE_5 = 1 << 5;
    uint256 internal constant _ROLE_6 = 1 << 6;
    uint256 internal constant _ROLE_7 = 1 << 7;
    uint256 internal constant _ROLE_8 = 1 << 8;
    uint256 internal constant _ROLE_9 = 1 << 9;
    uint256 internal constant _ROLE_10 = 1 << 10;
    uint256 internal constant _ROLE_11 = 1 << 11;
    uint256 internal constant _ROLE_12 = 1 << 12;
    uint256 internal constant _ROLE_13 = 1 << 13;
    uint256 internal constant _ROLE_14 = 1 << 14;
    uint256 internal constant _ROLE_15 = 1 << 15;
    uint256 internal constant _ROLE_16 = 1 << 16;
    uint256 internal constant _ROLE_17 = 1 << 17;
    uint256 internal constant _ROLE_18 = 1 << 18;
    uint256 internal constant _ROLE_19 = 1 << 19;
    uint256 internal constant _ROLE_20 = 1 << 20;
    uint256 internal constant _ROLE_21 = 1 << 21;
    uint256 internal constant _ROLE_22 = 1 << 22;
    uint256 internal constant _ROLE_23 = 1 << 23;
    uint256 internal constant _ROLE_24 = 1 << 24;
    uint256 internal constant _ROLE_25 = 1 << 25;
    uint256 internal constant _ROLE_26 = 1 << 26;
    uint256 internal constant _ROLE_27 = 1 << 27;
    uint256 internal constant _ROLE_28 = 1 << 28;
    uint256 internal constant _ROLE_29 = 1 << 29;
    uint256 internal constant _ROLE_30 = 1 << 30;
    uint256 internal constant _ROLE_31 = 1 << 31;
    uint256 internal constant _ROLE_32 = 1 << 32;
    uint256 internal constant _ROLE_33 = 1 << 33;
    uint256 internal constant _ROLE_34 = 1 << 34;
    uint256 internal constant _ROLE_35 = 1 << 35;
    uint256 internal constant _ROLE_36 = 1 << 36;
    uint256 internal constant _ROLE_37 = 1 << 37;
    uint256 internal constant _ROLE_38 = 1 << 38;
    uint256 internal constant _ROLE_39 = 1 << 39;
    uint256 internal constant _ROLE_40 = 1 << 40;
    uint256 internal constant _ROLE_41 = 1 << 41;
    uint256 internal constant _ROLE_42 = 1 << 42;
    uint256 internal constant _ROLE_43 = 1 << 43;
    uint256 internal constant _ROLE_44 = 1 << 44;
    uint256 internal constant _ROLE_45 = 1 << 45;
    uint256 internal constant _ROLE_46 = 1 << 46;
    uint256 internal constant _ROLE_47 = 1 << 47;
    uint256 internal constant _ROLE_48 = 1 << 48;
    uint256 internal constant _ROLE_49 = 1 << 49;
    uint256 internal constant _ROLE_50 = 1 << 50;
    uint256 internal constant _ROLE_51 = 1 << 51;
    uint256 internal constant _ROLE_52 = 1 << 52;
    uint256 internal constant _ROLE_53 = 1 << 53;
    uint256 internal constant _ROLE_54 = 1 << 54;
    uint256 internal constant _ROLE_55 = 1 << 55;
    uint256 internal constant _ROLE_56 = 1 << 56;
    uint256 internal constant _ROLE_57 = 1 << 57;
    uint256 internal constant _ROLE_58 = 1 << 58;
    uint256 internal constant _ROLE_59 = 1 << 59;
    uint256 internal constant _ROLE_60 = 1 << 60;
    uint256 internal constant _ROLE_61 = 1 << 61;
    uint256 internal constant _ROLE_62 = 1 << 62;
    uint256 internal constant _ROLE_63 = 1 << 63;
    uint256 internal constant _ROLE_64 = 1 << 64;
    uint256 internal constant _ROLE_65 = 1 << 65;
    uint256 internal constant _ROLE_66 = 1 << 66;
    uint256 internal constant _ROLE_67 = 1 << 67;
    uint256 internal constant _ROLE_68 = 1 << 68;
    uint256 internal constant _ROLE_69 = 1 << 69;
    uint256 internal constant _ROLE_70 = 1 << 70;
    uint256 internal constant _ROLE_71 = 1 << 71;
    uint256 internal constant _ROLE_72 = 1 << 72;
    uint256 internal constant _ROLE_73 = 1 << 73;
    uint256 internal constant _ROLE_74 = 1 << 74;
    uint256 internal constant _ROLE_75 = 1 << 75;
    uint256 internal constant _ROLE_76 = 1 << 76;
    uint256 internal constant _ROLE_77 = 1 << 77;
    uint256 internal constant _ROLE_78 = 1 << 78;
    uint256 internal constant _ROLE_79 = 1 << 79;
    uint256 internal constant _ROLE_80 = 1 << 80;
    uint256 internal constant _ROLE_81 = 1 << 81;
    uint256 internal constant _ROLE_82 = 1 << 82;
    uint256 internal constant _ROLE_83 = 1 << 83;
    uint256 internal constant _ROLE_84 = 1 << 84;
    uint256 internal constant _ROLE_85 = 1 << 85;
    uint256 internal constant _ROLE_86 = 1 << 86;
    uint256 internal constant _ROLE_87 = 1 << 87;
    uint256 internal constant _ROLE_88 = 1 << 88;
    uint256 internal constant _ROLE_89 = 1 << 89;
    uint256 internal constant _ROLE_90 = 1 << 90;
    uint256 internal constant _ROLE_91 = 1 << 91;
    uint256 internal constant _ROLE_92 = 1 << 92;
    uint256 internal constant _ROLE_93 = 1 << 93;
    uint256 internal constant _ROLE_94 = 1 << 94;
    uint256 internal constant _ROLE_95 = 1 << 95;
    uint256 internal constant _ROLE_96 = 1 << 96;
    uint256 internal constant _ROLE_97 = 1 << 97;
    uint256 internal constant _ROLE_98 = 1 << 98;
    uint256 internal constant _ROLE_99 = 1 << 99;
    uint256 internal constant _ROLE_100 = 1 << 100;
    uint256 internal constant _ROLE_101 = 1 << 101;
    uint256 internal constant _ROLE_102 = 1 << 102;
    uint256 internal constant _ROLE_103 = 1 << 103;
    uint256 internal constant _ROLE_104 = 1 << 104;
    uint256 internal constant _ROLE_105 = 1 << 105;
    uint256 internal constant _ROLE_106 = 1 << 106;
    uint256 internal constant _ROLE_107 = 1 << 107;
    uint256 internal constant _ROLE_108 = 1 << 108;
    uint256 internal constant _ROLE_109 = 1 << 109;
    uint256 internal constant _ROLE_110 = 1 << 110;
    uint256 internal constant _ROLE_111 = 1 << 111;
    uint256 internal constant _ROLE_112 = 1 << 112;
    uint256 internal constant _ROLE_113 = 1 << 113;
    uint256 internal constant _ROLE_114 = 1 << 114;
    uint256 internal constant _ROLE_115 = 1 << 115;
    uint256 internal constant _ROLE_116 = 1 << 116;
    uint256 internal constant _ROLE_117 = 1 << 117;
    uint256 internal constant _ROLE_118 = 1 << 118;
    uint256 internal constant _ROLE_119 = 1 << 119;
    uint256 internal constant _ROLE_120 = 1 << 120;
    uint256 internal constant _ROLE_121 = 1 << 121;
    uint256 internal constant _ROLE_122 = 1 << 122;
    uint256 internal constant _ROLE_123 = 1 << 123;
    uint256 internal constant _ROLE_124 = 1 << 124;
    uint256 internal constant _ROLE_125 = 1 << 125;
    uint256 internal constant _ROLE_126 = 1 << 126;
    uint256 internal constant _ROLE_127 = 1 << 127;
    uint256 internal constant _ROLE_128 = 1 << 128;
    uint256 internal constant _ROLE_129 = 1 << 129;
    uint256 internal constant _ROLE_130 = 1 << 130;
    uint256 internal constant _ROLE_131 = 1 << 131;
    uint256 internal constant _ROLE_132 = 1 << 132;
    uint256 internal constant _ROLE_133 = 1 << 133;
    uint256 internal constant _ROLE_134 = 1 << 134;
    uint256 internal constant _ROLE_135 = 1 << 135;
    uint256 internal constant _ROLE_136 = 1 << 136;
    uint256 internal constant _ROLE_137 = 1 << 137;
    uint256 internal constant _ROLE_138 = 1 << 138;
    uint256 internal constant _ROLE_139 = 1 << 139;
    uint256 internal constant _ROLE_140 = 1 << 140;
    uint256 internal constant _ROLE_141 = 1 << 141;
    uint256 internal constant _ROLE_142 = 1 << 142;
    uint256 internal constant _ROLE_143 = 1 << 143;
    uint256 internal constant _ROLE_144 = 1 << 144;
    uint256 internal constant _ROLE_145 = 1 << 145;
    uint256 internal constant _ROLE_146 = 1 << 146;
    uint256 internal constant _ROLE_147 = 1 << 147;
    uint256 internal constant _ROLE_148 = 1 << 148;
    uint256 internal constant _ROLE_149 = 1 << 149;
    uint256 internal constant _ROLE_150 = 1 << 150;
    uint256 internal constant _ROLE_151 = 1 << 151;
    uint256 internal constant _ROLE_152 = 1 << 152;
    uint256 internal constant _ROLE_153 = 1 << 153;
    uint256 internal constant _ROLE_154 = 1 << 154;
    uint256 internal constant _ROLE_155 = 1 << 155;
    uint256 internal constant _ROLE_156 = 1 << 156;
    uint256 internal constant _ROLE_157 = 1 << 157;
    uint256 internal constant _ROLE_158 = 1 << 158;
    uint256 internal constant _ROLE_159 = 1 << 159;
    uint256 internal constant _ROLE_160 = 1 << 160;
    uint256 internal constant _ROLE_161 = 1 << 161;
    uint256 internal constant _ROLE_162 = 1 << 162;
    uint256 internal constant _ROLE_163 = 1 << 163;
    uint256 internal constant _ROLE_164 = 1 << 164;
    uint256 internal constant _ROLE_165 = 1 << 165;
    uint256 internal constant _ROLE_166 = 1 << 166;
    uint256 internal constant _ROLE_167 = 1 << 167;
    uint256 internal constant _ROLE_168 = 1 << 168;
    uint256 internal constant _ROLE_169 = 1 << 169;
    uint256 internal constant _ROLE_170 = 1 << 170;
    uint256 internal constant _ROLE_171 = 1 << 171;
    uint256 internal constant _ROLE_172 = 1 << 172;
    uint256 internal constant _ROLE_173 = 1 << 173;
    uint256 internal constant _ROLE_174 = 1 << 174;
    uint256 internal constant _ROLE_175 = 1 << 175;
    uint256 internal constant _ROLE_176 = 1 << 176;
    uint256 internal constant _ROLE_177 = 1 << 177;
    uint256 internal constant _ROLE_178 = 1 << 178;
    uint256 internal constant _ROLE_179 = 1 << 179;
    uint256 internal constant _ROLE_180 = 1 << 180;
    uint256 internal constant _ROLE_181 = 1 << 181;
    uint256 internal constant _ROLE_182 = 1 << 182;
    uint256 internal constant _ROLE_183 = 1 << 183;
    uint256 internal constant _ROLE_184 = 1 << 184;
    uint256 internal constant _ROLE_185 = 1 << 185;
    uint256 internal constant _ROLE_186 = 1 << 186;
    uint256 internal constant _ROLE_187 = 1 << 187;
    uint256 internal constant _ROLE_188 = 1 << 188;
    uint256 internal constant _ROLE_189 = 1 << 189;
    uint256 internal constant _ROLE_190 = 1 << 190;
    uint256 internal constant _ROLE_191 = 1 << 191;
    uint256 internal constant _ROLE_192 = 1 << 192;
    uint256 internal constant _ROLE_193 = 1 << 193;
    uint256 internal constant _ROLE_194 = 1 << 194;
    uint256 internal constant _ROLE_195 = 1 << 195;
    uint256 internal constant _ROLE_196 = 1 << 196;
    uint256 internal constant _ROLE_197 = 1 << 197;
    uint256 internal constant _ROLE_198 = 1 << 198;
    uint256 internal constant _ROLE_199 = 1 << 199;
    uint256 internal constant _ROLE_200 = 1 << 200;
    uint256 internal constant _ROLE_201 = 1 << 201;
    uint256 internal constant _ROLE_202 = 1 << 202;
    uint256 internal constant _ROLE_203 = 1 << 203;
    uint256 internal constant _ROLE_204 = 1 << 204;
    uint256 internal constant _ROLE_205 = 1 << 205;
    uint256 internal constant _ROLE_206 = 1 << 206;
    uint256 internal constant _ROLE_207 = 1 << 207;
    uint256 internal constant _ROLE_208 = 1 << 208;
    uint256 internal constant _ROLE_209 = 1 << 209;
    uint256 internal constant _ROLE_210 = 1 << 210;
    uint256 internal constant _ROLE_211 = 1 << 211;
    uint256 internal constant _ROLE_212 = 1 << 212;
    uint256 internal constant _ROLE_213 = 1 << 213;
    uint256 internal constant _ROLE_214 = 1 << 214;
    uint256 internal constant _ROLE_215 = 1 << 215;
    uint256 internal constant _ROLE_216 = 1 << 216;
    uint256 internal constant _ROLE_217 = 1 << 217;
    uint256 internal constant _ROLE_218 = 1 << 218;
    uint256 internal constant _ROLE_219 = 1 << 219;
    uint256 internal constant _ROLE_220 = 1 << 220;
    uint256 internal constant _ROLE_221 = 1 << 221;
    uint256 internal constant _ROLE_222 = 1 << 222;
    uint256 internal constant _ROLE_223 = 1 << 223;
    uint256 internal constant _ROLE_224 = 1 << 224;
    uint256 internal constant _ROLE_225 = 1 << 225;
    uint256 internal constant _ROLE_226 = 1 << 226;
    uint256 internal constant _ROLE_227 = 1 << 227;
    uint256 internal constant _ROLE_228 = 1 << 228;
    uint256 internal constant _ROLE_229 = 1 << 229;
    uint256 internal constant _ROLE_230 = 1 << 230;
    uint256 internal constant _ROLE_231 = 1 << 231;
    uint256 internal constant _ROLE_232 = 1 << 232;
    uint256 internal constant _ROLE_233 = 1 << 233;
    uint256 internal constant _ROLE_234 = 1 << 234;
    uint256 internal constant _ROLE_235 = 1 << 235;
    uint256 internal constant _ROLE_236 = 1 << 236;
    uint256 internal constant _ROLE_237 = 1 << 237;
    uint256 internal constant _ROLE_238 = 1 << 238;
    uint256 internal constant _ROLE_239 = 1 << 239;
    uint256 internal constant _ROLE_240 = 1 << 240;
    uint256 internal constant _ROLE_241 = 1 << 241;
    uint256 internal constant _ROLE_242 = 1 << 242;
    uint256 internal constant _ROLE_243 = 1 << 243;
    uint256 internal constant _ROLE_244 = 1 << 244;
    uint256 internal constant _ROLE_245 = 1 << 245;
    uint256 internal constant _ROLE_246 = 1 << 246;
    uint256 internal constant _ROLE_247 = 1 << 247;
    uint256 internal constant _ROLE_248 = 1 << 248;
    uint256 internal constant _ROLE_249 = 1 << 249;
    uint256 internal constant _ROLE_250 = 1 << 250;
    uint256 internal constant _ROLE_251 = 1 << 251;
    uint256 internal constant _ROLE_252 = 1 << 252;
    uint256 internal constant _ROLE_253 = 1 << 253;
    uint256 internal constant _ROLE_254 = 1 << 254;
    uint256 internal constant _ROLE_255 = 1 << 255;
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

/// @notice Simple single owner authorization mixin.
/// @author Solady (https://github.com/vectorized/solady/blob/main/src/auth/Ownable.sol)
///
/// @dev Note:
/// This implementation does NOT auto-initialize the owner to `msg.sender`.
/// You MUST call the `_initializeOwner` in the constructor / initializer.
///
/// While the ownable portion follows
/// [EIP-173](https://eips.ethereum.org/EIPS/eip-173) for compatibility,
/// the nomenclature for the 2-step ownership handover may be unique to this codebase.
abstract contract Ownable {
    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                       CUSTOM ERRORS                        */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev The caller is not authorized to call the function.
    error Unauthorized();

    /// @dev The `newOwner` cannot be the zero address.
    error NewOwnerIsZeroAddress();

    /// @dev The `pendingOwner` does not have a valid handover request.
    error NoHandoverRequest();

    /// @dev Cannot double-initialize.
    error AlreadyInitialized();

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                           EVENTS                           */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev The ownership is transferred from `oldOwner` to `newOwner`.
    /// This event is intentionally kept the same as OpenZeppelin's Ownable to be
    /// compatible with indexers and [EIP-173](https://eips.ethereum.org/EIPS/eip-173),
    /// despite it not being as lightweight as a single argument event.
    event OwnershipTransferred(address indexed oldOwner, address indexed newOwner);

    /// @dev An ownership handover to `pendingOwner` has been requested.
    event OwnershipHandoverRequested(address indexed pendingOwner);

    /// @dev The ownership handover to `pendingOwner` has been canceled.
    event OwnershipHandoverCanceled(address indexed pendingOwner);

    /// @dev `keccak256(bytes("OwnershipTransferred(address,address)"))`.
    uint256 private constant _OWNERSHIP_TRANSFERRED_EVENT_SIGNATURE =
        0x8be0079c531659141344cd1fd0a4f28419497f9722a3daafe3b4186f6b6457e0;

    /// @dev `keccak256(bytes("OwnershipHandoverRequested(address)"))`.
    uint256 private constant _OWNERSHIP_HANDOVER_REQUESTED_EVENT_SIGNATURE =
        0xdbf36a107da19e49527a7176a1babf963b4b0ff8cde35ee35d6cd8f1f9ac7e1d;

    /// @dev `keccak256(bytes("OwnershipHandoverCanceled(address)"))`.
    uint256 private constant _OWNERSHIP_HANDOVER_CANCELED_EVENT_SIGNATURE =
        0xfa7b8eab7da67f412cc9575ed43464468f9bfbae89d1675917346ca6d8fe3c92;

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                          STORAGE                           */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev The owner slot is given by:
    /// `bytes32(~uint256(uint32(bytes4(keccak256("_OWNER_SLOT_NOT")))))`.
    /// It is intentionally chosen to be a high value
    /// to avoid collision with lower slots.
    /// The choice of manual storage layout is to enable compatibility
    /// with both regular and upgradeable contracts.
    bytes32 internal constant _OWNER_SLOT =
        0xffffffffffffffffffffffffffffffffffffffffffffffffffffffff74873927;

    /// The ownership handover slot of `newOwner` is given by:
    /// ```
    ///     mstore(0x00, or(shl(96, user), _HANDOVER_SLOT_SEED))
    ///     let handoverSlot := keccak256(0x00, 0x20)
    /// ```
    /// It stores the expiry timestamp of the two-step ownership handover.
    uint256 private constant _HANDOVER_SLOT_SEED = 0x389a75e1;

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                     INTERNAL FUNCTIONS                     */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Override to return true to make `_initializeOwner` prevent double-initialization.
    function _guardInitializeOwner() internal pure virtual returns (bool guard) {}

    /// @dev Initializes the owner directly without authorization guard.
    /// This function must be called upon initialization,
    /// regardless of whether the contract is upgradeable or not.
    /// This is to enable generalization to both regular and upgradeable contracts,
    /// and to save gas in case the initial owner is not the caller.
    /// For performance reasons, this function will not check if there
    /// is an existing owner.
    function _initializeOwner(address newOwner) internal virtual {
        if (_guardInitializeOwner()) {
            /// @solidity memory-safe-assembly
            assembly {
                let ownerSlot := _OWNER_SLOT
                if sload(ownerSlot) {
                    mstore(0x00, 0x0dc149f0) // `AlreadyInitialized()`.
                    revert(0x1c, 0x04)
                }
                // Clean the upper 96 bits.
                newOwner := shr(96, shl(96, newOwner))
                // Store the new value.
                sstore(ownerSlot, or(newOwner, shl(255, iszero(newOwner))))
                // Emit the {OwnershipTransferred} event.
                log3(0, 0, _OWNERSHIP_TRANSFERRED_EVENT_SIGNATURE, 0, newOwner)
            }
        } else {
            /// @solidity memory-safe-assembly
            assembly {
                // Clean the upper 96 bits.
                newOwner := shr(96, shl(96, newOwner))
                // Store the new value.
                sstore(_OWNER_SLOT, newOwner)
                // Emit the {OwnershipTransferred} event.
                log3(0, 0, _OWNERSHIP_TRANSFERRED_EVENT_SIGNATURE, 0, newOwner)
            }
        }
    }

    /// @dev Sets the owner directly without authorization guard.
    function _setOwner(address newOwner) internal virtual {
        if (_guardInitializeOwner()) {
            /// @solidity memory-safe-assembly
            assembly {
                let ownerSlot := _OWNER_SLOT
                // Clean the upper 96 bits.
                newOwner := shr(96, shl(96, newOwner))
                // Emit the {OwnershipTransferred} event.
                log3(0, 0, _OWNERSHIP_TRANSFERRED_EVENT_SIGNATURE, sload(ownerSlot), newOwner)
                // Store the new value.
                sstore(ownerSlot, or(newOwner, shl(255, iszero(newOwner))))
            }
        } else {
            /// @solidity memory-safe-assembly
            assembly {
                let ownerSlot := _OWNER_SLOT
                // Clean the upper 96 bits.
                newOwner := shr(96, shl(96, newOwner))
                // Emit the {OwnershipTransferred} event.
                log3(0, 0, _OWNERSHIP_TRANSFERRED_EVENT_SIGNATURE, sload(ownerSlot), newOwner)
                // Store the new value.
                sstore(ownerSlot, newOwner)
            }
        }
    }

    /// @dev Throws if the sender is not the owner.
    function _checkOwner() internal view virtual {
        /// @solidity memory-safe-assembly
        assembly {
            // If the caller is not the stored owner, revert.
            if iszero(eq(caller(), sload(_OWNER_SLOT))) {
                mstore(0x00, 0x82b42900) // `Unauthorized()`.
                revert(0x1c, 0x04)
            }
        }
    }

    /// @dev Returns how long a two-step ownership handover is valid for in seconds.
    /// Override to return a different value if needed.
    /// Made internal to conserve bytecode. Wrap it in a public function if needed.
    function _ownershipHandoverValidFor() internal view virtual returns (uint64) {
        return 48 * 3600;
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                  PUBLIC UPDATE FUNCTIONS                   */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Allows the owner to transfer the ownership to `newOwner`.
    function transferOwnership(address newOwner) public payable virtual onlyOwner {
        /// @solidity memory-safe-assembly
        assembly {
            if iszero(shl(96, newOwner)) {
                mstore(0x00, 0x7448fbae) // `NewOwnerIsZeroAddress()`.
                revert(0x1c, 0x04)
            }
        }
        _setOwner(newOwner);
    }

    /// @dev Allows the owner to renounce their ownership.
    function renounceOwnership() public payable virtual onlyOwner {
        _setOwner(address(0));
    }

    /// @dev Request a two-step ownership handover to the caller.
    /// The request will automatically expire in 48 hours (172800 seconds) by default.
    function requestOwnershipHandover() public payable virtual {
        unchecked {
            uint256 expires = block.timestamp + _ownershipHandoverValidFor();
            /// @solidity memory-safe-assembly
            assembly {
                // Compute and set the handover slot to `expires`.
                mstore(0x0c, _HANDOVER_SLOT_SEED)
                mstore(0x00, caller())
                sstore(keccak256(0x0c, 0x20), expires)
                // Emit the {OwnershipHandoverRequested} event.
                log2(0, 0, _OWNERSHIP_HANDOVER_REQUESTED_EVENT_SIGNATURE, caller())
            }
        }
    }

    /// @dev Cancels the two-step ownership handover to the caller, if any.
    function cancelOwnershipHandover() public payable virtual {
        /// @solidity memory-safe-assembly
        assembly {
            // Compute and set the handover slot to 0.
            mstore(0x0c, _HANDOVER_SLOT_SEED)
            mstore(0x00, caller())
            sstore(keccak256(0x0c, 0x20), 0)
            // Emit the {OwnershipHandoverCanceled} event.
            log2(0, 0, _OWNERSHIP_HANDOVER_CANCELED_EVENT_SIGNATURE, caller())
        }
    }

    /// @dev Allows the owner to complete the two-step ownership handover to `pendingOwner`.
    /// Reverts if there is no existing ownership handover requested by `pendingOwner`.
    function completeOwnershipHandover(address pendingOwner) public payable virtual onlyOwner {
        /// @solidity memory-safe-assembly
        assembly {
            // Compute and set the handover slot to 0.
            mstore(0x0c, _HANDOVER_SLOT_SEED)
            mstore(0x00, pendingOwner)
            let handoverSlot := keccak256(0x0c, 0x20)
            // If the handover does not exist, or has expired.
            if gt(timestamp(), sload(handoverSlot)) {
                mstore(0x00, 0x6f5e8818) // `NoHandoverRequest()`.
                revert(0x1c, 0x04)
            }
            // Set the handover slot to 0.
            sstore(handoverSlot, 0)
        }
        _setOwner(pendingOwner);
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                   PUBLIC READ FUNCTIONS                    */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Returns the owner of the contract.
    function owner() public view virtual returns (address result) {
        /// @solidity memory-safe-assembly
        assembly {
            result := sload(_OWNER_SLOT)
        }
    }

    /// @dev Returns the expiry timestamp for the two-step ownership handover to `pendingOwner`.
    function ownershipHandoverExpiresAt(address pendingOwner)
        public
        view
        virtual
        returns (uint256 result)
    {
        /// @solidity memory-safe-assembly
        assembly {
            // Compute the handover slot.
            mstore(0x0c, _HANDOVER_SLOT_SEED)
            mstore(0x00, pendingOwner)
            // Load the handover slot.
            result := sload(keccak256(0x0c, 0x20))
        }
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                         MODIFIERS                          */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Marks a function as only callable by the owner.
    modifier onlyOwner() virtual {
        _checkOwner();
        _;
    }
}