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IPublicLockV12

The PublicLock Interface

Methods

DEFAULT_ADMIN_ROLE

function DEFAULT_ADMIN_ROLE() external view returns (bytes32 role)

Returns

NameTypeDescription
rolebytes32undefined

KEY_GRANTER_ROLE

function KEY_GRANTER_ROLE() external view returns (bytes32 role)

Returns

NameTypeDescription
rolebytes32undefined

LOCK_MANAGER_ROLE

function LOCK_MANAGER_ROLE() external view returns (bytes32 role)

Returns

NameTypeDescription
rolebytes32undefined

addKeyGranter

function addKeyGranter(address account) external nonpayable

Parameters

NameTypeDescription
accountaddressundefined

addLockManager

function addLockManager(address account) external nonpayable

Parameters

NameTypeDescription
accountaddressundefined

approve

function approve(address to, uint256 tokenId) external nonpayable

Parameters

NameTypeDescription
toaddressundefined
tokenIduint256undefined

balanceOf

function balanceOf(address _owner) external view returns (uint256 balance)

In the specific case of a Lock, balanceOf returns only the tokens with a valid expiration timerange

Parameters

NameTypeDescription
_owneraddressundefined

Returns

NameTypeDescription
balanceuint256The number of valid keys owned by _keyOwner

burn

function burn(uint256 _tokenId) external nonpayable

Deactivate an existing keythe key will be expired and ownership records will be destroyed

Parameters

NameTypeDescription
_tokenIduint256the id of token to burn

cancelAndRefund

function cancelAndRefund(uint256 _tokenId) external nonpayable

allows the key manager to expire a given tokenId and send a refund to the keyOwner based on the amount of time remaining.

Parameters

NameTypeDescription
_tokenIduint256The id of the key to cancel.

expirationDuration

function expirationDuration() external view returns (uint256)

Returns

NameTypeDescription
_0uint256undefined

expireAndRefundFor

function expireAndRefundFor(uint256 _tokenId, uint256 _amount) external nonpayable

Invoked by a Lock manager to expire the user's key and perform a refund and cancellation of the keyThrows if called by other than a Lock managerThrows if _keyOwner does not have a valid key

Parameters

NameTypeDescription
_tokenIduint256The key id we wish to refund to
_amountuint256The amount to refund to the key-owner

extend

function extend(uint256 _value, uint256 _tokenId, address _referrer, bytes _data) external payable

Extend functionThrows if lock is disabled or key does not exist for _recipient. Throws if _recipient == address(0).

Parameters

NameTypeDescription
_valueuint256the number of tokens to pay for this purchase >= the current keyPrice - any applicable discount (_value is ignored when using ETH)
_tokenIduint256the id of the key to extend
_referreraddressaddress of the user making the referral
_databytesarbitrary data populated by the front-end which initiated the sale

freeTrialLength

function freeTrialLength() external view returns (uint256)

Returns

NameTypeDescription
_0uint256undefined

gasRefundValue

function gasRefundValue() external view returns (uint256 _gasRefundValue)

_gasRefundValue price in wei or token in smallest price unit

Returns the value/rpice to be refunded to the sender on purchase

Returns

NameTypeDescription
_gasRefundValueuint256undefined

getApproved

function getApproved(uint256 _tokenId) external view returns (address operator)

Get the approved address for a single NFT

Throws if _tokenId is not a valid NFT.

Parameters

NameTypeDescription
_tokenIduint256The NFT to find the approved address for

Returns

NameTypeDescription
operatoraddressThe approved address for this NFT, or the zero address if there is none

getCancelAndRefundValue

function getCancelAndRefundValue(uint256 _tokenId) external view returns (uint256 refund)

Due to the time required to mine a tx, the actual refund amount will be lower than what the user reads from this call.

Determines how much of a refund a key owner would receive if they issued

Parameters

NameTypeDescription
_tokenIduint256the id of the token to get the refund value for.

Returns

NameTypeDescription
refunduint256the amount of tokens refunded

getHasValidKey

function getHasValidKey(address _user) external view returns (bool)

Checks if the user has a non-expired key.

Parameters

NameTypeDescription
_useraddressThe address of the key owner

Returns

NameTypeDescription
_0boolundefined

getRoleAdmin

function getRoleAdmin(bytes32 role) external view returns (bytes32)

Innherited from Open Zeppelin AccessControl.sol

Parameters

NameTypeDescription
rolebytes32undefined

Returns

NameTypeDescription
_0bytes32undefined

getTransferFee

function getTransferFee(uint256 _tokenId, uint256 _time) external view returns (uint256)

Determines how much of a fee would need to be paid in order to transfer to another account. This is pro-rated so the fee goes down overtime.

Throws if _tokenId does not have a valid key

Parameters

NameTypeDescription
_tokenIduint256The id of the key check the transfer fee for.
_timeuint256The amount of time to calculate the fee for.

Returns

NameTypeDescription
_0uint256The transfer fee in seconds.

grantKeyExtension

function grantKeyExtension(uint256 _tokenId, uint256 _duration) external nonpayable

Allows the Lock owner to extend an existing keys with no charge.

set _duration to 0 to use the default duration of the lock

Parameters

NameTypeDescription
_tokenIduint256The id of the token to extend
_durationuint256The duration in secondes to add ot the key

grantKeys

function grantKeys(address[] _recipients, uint256[] _expirationTimestamps, address[] _keyManagers) external nonpayable returns (uint256[])

Allows a Lock manager to give a collection of users a key with no charge. Each key may be assigned a different expiration date.

Throws if called by other than a Lock manager

Parameters

NameTypeDescription
_recipientsaddress[]An array of receiving addresses
_expirationTimestampsuint256[]An array of expiration Timestamps for the keys being granted
_keyManagersaddress[]undefined

Returns

NameTypeDescription
_0uint256[]the ids of the granted tokens

grantRole

function grantRole(bytes32 role, address account) external nonpayable

Parameters

NameTypeDescription
rolebytes32undefined
accountaddressundefined

hasRole

function hasRole(bytes32 role, address account) external view returns (bool)

Parameters

NameTypeDescription
rolebytes32undefined
accountaddressundefined

Returns

NameTypeDescription
_0boolundefined

initialize

function initialize(address _lockCreator, uint256 _expirationDuration, address _tokenAddress, uint256 _keyPrice, uint256 _maxNumberOfKeys, string _lockName) external nonpayable

Functions

Parameters

NameTypeDescription
_lockCreatoraddressundefined
_expirationDurationuint256undefined
_tokenAddressaddressundefined
_keyPriceuint256undefined
_maxNumberOfKeysuint256undefined
_lockNamestringundefined

isApprovedForAll

function isApprovedForAll(address _owner, address _operator) external view returns (bool)

Tells whether an operator is approved by a given keyManager

Parameters

NameTypeDescription
_owneraddressowner address which you want to query the approval of
_operatoraddressoperator address which you want to query the approval of

Returns

NameTypeDescription
_0boolbool whether the given operator is approved by the given owner

isKeyGranter

function isKeyGranter(address account) external view returns (bool)

Parameters

NameTypeDescription
accountaddressundefined

Returns

NameTypeDescription
_0boolundefined

isLockManager

function isLockManager(address account) external view returns (bool)

Parameters

NameTypeDescription
accountaddressundefined

Returns

NameTypeDescription
_0boolundefined

isOwner

function isOwner(address account) external view returns (bool isOwner)

Parameters

NameTypeDescription
accountaddressundefined

Returns

NameTypeDescription
isOwnerboolundefined

isValidKey

function isValidKey(uint256 _tokenId) external view returns (bool)

Check if a certain key is validthis makes use of the onValidKeyHook if it is set

Parameters

NameTypeDescription
_tokenIduint256the id of the key to check validity

Returns

NameTypeDescription
_0boolundefined

keyExpirationTimestampFor

function keyExpirationTimestampFor(uint256 _tokenId) external view returns (uint256 timestamp)

Returns the key's ExpirationTimestamp field for a given owner.Returns 0 if the owner has never owned a key for this lock

Parameters

NameTypeDescription
_tokenIduint256the id of the key

Returns

NameTypeDescription
timestampuint256undefined

keyManagerOf

function keyManagerOf(uint256) external view returns (address)

Parameters

NameTypeDescription
_0uint256undefined

Returns

NameTypeDescription
_0addressundefined

keyPrice

function keyPrice() external view returns (uint256)

Returns

NameTypeDescription
_0uint256undefined

lendKey

function lendKey(address from, address to, uint256 tokenId) external nonpayable

Lending a key allows you to transfer the token while retaining the ownerships right by setting yourself as a key manager first.This function can only be called by 1) the key owner when no key manager is set or 2) the key manager. After calling the function, the _recipent will be the new owner, and the sender of the tx will become the key manager.

Parameters

NameTypeDescription
fromaddressthe owner of token to transfer
toaddressthe address that will receive the token
tokenIduint256the id of the token

maxKeysPerAddress

function maxKeysPerAddress() external view returns (uint256)

Returns

NameTypeDescription
_0uint256the maximum number of key allowed for a single address

maxNumberOfKeys

function maxNumberOfKeys() external view returns (uint256)

Returns

NameTypeDescription
_0uint256undefined

mergeKeys

function mergeKeys(uint256 _tokenIdFrom, uint256 _tokenIdTo, uint256 _amount) external nonpayable

Merge existing keys

Parameters

NameTypeDescription
_tokenIdFromuint256the id of the token to substract time from
_tokenIdTouint256the id of the destination token to add time
_amountuint256the amount of time to transfer (in seconds)

migrate

function migrate(bytes _calldata) external nonpayable

Migrate data from the previous single owner => key mapping to the new data structure w multiple tokens.

when all record schemas are sucessfully upgraded, this function will update the schemaVersion variable to the latest/current lock version

Parameters

NameTypeDescription
_calldatabytesan ABI-encoded representation of the params (v10: the number of records to migrate as uint)

name

function name() external view returns (string _name)

A descriptive name for a collection of NFTs in this contract

Returns

NameTypeDescription
_namestringundefined

numberOfOwners

function numberOfOwners() external view returns (uint256)

Public function which returns the total number of unique owners (both expired and valid). This may be larger than totalSupply.

Returns

NameTypeDescription
_0uint256undefined

onKeyCancelHook

function onKeyCancelHook() external view returns (address hookAddress)

Returns the address of the onKeyCancelHook hook.

Returns

NameTypeDescription
hookAddressaddressaddress of the hook

onKeyExtendHook

function onKeyExtendHook() external view returns (address hookAddress)

Returns the address of the onKeyExtendHook hook.

Returns

NameTypeDescription
hookAddressaddressthe address ok the hook

onKeyGrantHook

function onKeyGrantHook() external view returns (address hookAddress)

Returns the address of the onKeyGrantHook hook.

Returns

NameTypeDescription
hookAddressaddressthe address ok the hook

onKeyPurchaseHook

function onKeyPurchaseHook() external view returns (address hookAddress)

Returns the address of the onKeyPurchaseHook hook.

Returns

NameTypeDescription
hookAddressaddressaddress of the hook

onKeyTransferHook

function onKeyTransferHook() external view returns (address hookAddress)

Returns the address of the onKeyTransferHook hook.

Returns

NameTypeDescription
hookAddressaddressaddress of the hook

onTokenURIHook

function onTokenURIHook() external view returns (address hookAddress)

Returns the address of the onTokenURIHook hook.

Returns

NameTypeDescription
hookAddressaddressaddress of the hook

onValidKeyHook

function onValidKeyHook() external view returns (address hookAddress)

Returns the address of the onValidKeyHook hook.

Returns

NameTypeDescription
hookAddressaddressaddress of the hook

owner

function owner() external view returns (address owner)

owner() is provided as an helper to mimick the Ownable contract ABI. The Ownable logic is used by many 3rd party services to determine contract ownership - e.g. who is allowed to edit metadata on Opensea.This logic is NOT used internally by the Unlock Protocol and is made available only as a convenience helper.

Returns

NameTypeDescription
owneraddressundefined

ownerOf

function ownerOf(uint256 tokenId) external view returns (address _owner)

Returns the owner of the NFT specified by tokenId.

Parameters

NameTypeDescription
tokenIduint256undefined

Returns

NameTypeDescription
_owneraddressundefined

publicLockVersion

function publicLockVersion() external pure returns (uint16)

The version number of the current implementation on this network.

Returns

NameTypeDescription
_0uint16The current version number.

purchase

function purchase(uint256[] _values, address[] _recipients, address[] _referrers, address[] _keyManagers, bytes[] _data) external payable returns (uint256[] tokenIds)

when called for an existing and non-expired key, the _keyManager param will be ignored

Purchase functionSetting _value to keyPrice exactly doubles as a security feature. That way if the lock owner increases the price while my transaction is pending I can't be charged more than I expected (only applicable to ERC-20 when more than keyPrice is approved for spending).

Parameters

NameTypeDescription
_valuesuint256[]array of tokens amount to pay for this purchase >= the current keyPrice - any applicable discount (_values is ignored when using ETH)
_recipientsaddress[]array of addresses of the recipients of the purchased key
_referrersaddress[]array of addresses of the users making the referral
_keyManagersaddress[]optional array of addresses to grant managing rights to a specific address on creation
_databytes[]array of arbitrary data populated by the front-end which initiated the sale

Returns

NameTypeDescription
tokenIdsuint256[]the ids of the created tokens

purchasePriceFor

function purchasePriceFor(address _recipient, address _referrer, bytes _data) external view returns (uint256)

returns the minimum price paid for a purchase with these params.

this considers any discount from Unlock or the OnKeyPurchase hook.

Parameters

NameTypeDescription
_recipientaddressundefined
_referreraddressundefined
_databytesundefined

Returns

NameTypeDescription
_0uint256undefined

referrerFees

function referrerFees(address _referrer) external view returns (uint256 referrerFee)

Returns the percentage of the keyPrice to be sent to the referrer (in basis points)

Parameters

NameTypeDescription
_referreraddressthe address of the referrer

Returns

NameTypeDescription
referrerFeeuint256the percentage of the keyPrice to be sent to the referrer (in basis points)

refundPenaltyBasisPoints

function refundPenaltyBasisPoints() external view returns (uint256)

Returns

NameTypeDescription
_0uint256undefined

renewMembershipFor

function renewMembershipFor(uint256 _tokenId, address _referrer) external nonpayable

Renew a given tokenonly works for non-free, expiring, ERC20 locks

Parameters

NameTypeDescription
_tokenIduint256the ID fo the token to renew
_referreraddressthe address of the person to be granted UDT

renounceLockManager

function renounceLockManager() external nonpayable

renounceRole

function renounceRole(bytes32 role, address account) external nonpayable

Parameters

NameTypeDescription
rolebytes32undefined
accountaddressundefined

revokeKeyGranter

function revokeKeyGranter(address _granter) external nonpayable

Parameters

NameTypeDescription
_granteraddressundefined

revokeRole

function revokeRole(bytes32 role, address account) external nonpayable

Parameters

NameTypeDescription
rolebytes32undefined
accountaddressundefined

safeTransferFrom

function safeTransferFrom(address from, address to, uint256 tokenId) external nonpayable

Transfers a specific NFT (tokenId) from one account (from) to another (to). Requirements: - from, to cannot be zero. - tokenId must be owned by from. - If the caller is not from, it must be have been allowed to move this NFT by either approve or setApprovalForAll.

Parameters

NameTypeDescription
fromaddressundefined
toaddressundefined
tokenIduint256undefined

safeTransferFrom

function safeTransferFrom(address from, address to, uint256 tokenId, bytes data) external nonpayable

Parameters

NameTypeDescription
fromaddressundefined
toaddressundefined
tokenIduint256undefined
databytesundefined

schemaVersion

function schemaVersion() external view returns (uint256)

Returns the version number of the data schema currently used by the lockif this is different from publicLockVersion, then the ability to purchase, grant or extend keys is disabled.

will return 0 if no ;igration has ever been run

Returns

NameTypeDescription
_0uint256undefined

setApprovalForAll

function setApprovalForAll(address _operator, bool _approved) external nonpayable

disabled when transfers are disabled

Sets or unsets the approval of a given operator An operator is allowed to transfer all tokens of the sender on their behalf

Parameters

NameTypeDescription
_operatoraddressoperator address to set the approval
_approvedboolrepresenting the status of the approval to be set

setEventHooks

function setEventHooks(address _onKeyPurchaseHook, address _onKeyCancelHook, address _onValidKeyHook, address _onTokenURIHook, address _onKeyTransferHook, address _onKeyExtendHook, address _onKeyGrantHook) external nonpayable

Allows a Lock manager to add or remove an event hook

Parameters

NameTypeDescription
_onKeyPurchaseHookaddressHook called when the purchase function is called
_onKeyCancelHookaddressHook called when the internal _cancelAndRefund function is called
_onValidKeyHookaddressHook called to determine if the contract should overide the status for a given address
_onTokenURIHookaddressHook called to generate a data URI used for NFT metadata
_onKeyTransferHookaddressHook called when a key is transfered
_onKeyExtendHookaddressHook called when a key is extended or renewed
_onKeyGrantHookaddressHook called when a key is granted

setGasRefundValue

function setGasRefundValue(uint256 _gasRefundValue) external nonpayable

Set the value to be refunded to the sender on purchase

Parameters

NameTypeDescription
_gasRefundValueuint256price in wei or token in smallest price unit

setKeyManagerOf

function setKeyManagerOf(uint256 _tokenId, address _keyManager) external nonpayable

Update transfer and cancel rights for a given key

Parameters

NameTypeDescription
_tokenIduint256The id of the key to assign rights for
_keyManageraddressThe address to assign the rights to for the given key

setLockMetadata

function setLockMetadata(string _lockName, string _lockSymbol, string _baseTokenURI) external nonpayable

Allows the Lock owner to assign

Parameters

NameTypeDescription
_lockNamestringa descriptive name for this Lock.
_lockSymbolstringa Symbol for this Lock (default to KEY).
_baseTokenURIstringthe baseTokenURI for this Lock

setOwner

function setOwner(address account) external nonpayable

Parameters

NameTypeDescription
accountaddressundefined

setReferrerFee

function setReferrerFee(address _referrer, uint256 _feeBasisPoint) external nonpayable

Set a specific percentage of the keyPrice to be sent to the referrer while purchasing, extending or renewing a key.

To send a fixed percentage of the key price to all referrers, sett a percentage to address(0)

Parameters

NameTypeDescription
_referreraddressthe address of the referrer
_feeBasisPointuint256the percentage of the price to be used for this specific referrer (in basis points)

shareKey

function shareKey(address _to, uint256 _tokenId, uint256 _timeShared) external nonpayable

Allows the key owner to safely share their key (parent key) by transferring a portion of the remaining time to a new key (child key).

Throws if key is not valid.Throws if _to is the zero addressEmit Transfer event

Parameters

NameTypeDescription
_toaddressThe recipient of the shared key
_tokenIduint256the key to share
_timeShareduint256The amount of time shared checks if _to is a smart contract (code size > 0). If so, it calls onERC721Received on _to and throws if the return value is not bytes4(keccak256('onERC721Received(address,address,uint,bytes)')).

supportsInterface

function supportsInterface(bytes4 interfaceId) external view returns (bool)

From ERC165.sol

Parameters

NameTypeDescription
interfaceIdbytes4undefined

Returns

NameTypeDescription
_0boolundefined

symbol

function symbol() external view returns (string)

Gets the token symbol

Returns

NameTypeDescription
_0stringstring representing the token symbol

tokenAddress

function tokenAddress() external view returns (address)

Returns

NameTypeDescription
_0addressundefined

tokenByIndex

function tokenByIndex(uint256 index) external view returns (uint256)

Parameters

NameTypeDescription
indexuint256undefined

Returns

NameTypeDescription
_0uint256undefined

tokenOfOwnerByIndex

function tokenOfOwnerByIndex(address _owner, uint256 index) external view returns (uint256 tokenId)

Parameters

NameTypeDescription
_owneraddressundefined
indexuint256undefined

Returns

NameTypeDescription
tokenIduint256undefined

tokenURI

function tokenURI(uint256 _tokenId) external view returns (string)

A distinct Uniform Resource Identifier (URI) for a given asset.

Throws if _tokenId is not a valid NFT. URIs are defined in RFC 3986. The URI may point to a JSON file that conforms to the "ERC721 Metadata JSON Schema". https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md

Parameters

NameTypeDescription
_tokenIduint256The tokenID we're inquiring about

Returns

NameTypeDescription
_0stringString representing the URI for the requested token

totalKeys

function totalKeys(address _keyOwner) external view returns (uint256 numberOfKeys)

Returns the number of keys owned by _keyOwner (expired or not)

Parameters

NameTypeDescription
_keyOwneraddressaddress for which we are retrieving the total number of keys

Returns

NameTypeDescription
numberOfKeysuint256total number of keys owned by the address

totalSupply

function totalSupply() external view returns (uint256)

Returns

NameTypeDescription
_0uint256undefined

transfer

function transfer(uint256 _tokenId, address _to, uint256 _value) external nonpayable returns (bool success)

The typical use case would be to call this with _value 1, which is on par with calling transferFrom. If the user has more than expirationDuration time remaining this may use the shareKey function to send some but not all of the token.

Parameters

NameTypeDescription
_tokenIduint256the id of the token to transfer time from
_toaddressthe recipient of the new token with time
_valueuint256sends a token with _value * expirationDuration (the amount of time remaining on a standard purchase).

Returns

NameTypeDescription
successboolthe result of the transfer operation

transferFeeBasisPoints

function transferFeeBasisPoints() external view returns (uint256)

Returns

NameTypeDescription
_0uint256undefined

transferFrom

function transferFrom(address from, address to, uint256 tokenId) external nonpayable

an ERC721-like function to transfer a token from one account to another.

Requirements: if the caller is not from, it must be approved to move this token by either approve or setApprovalForAll. The key manager will be reset to address zero after the transfer

Parameters

NameTypeDescription
fromaddressthe owner of token to transfer
toaddressthe address that will receive the token
tokenIduint256the id of the token

unlendKey

function unlendKey(address _recipient, uint256 _tokenId) external nonpayable

Unlend is called when you have lent a key and want to claim its full ownership back.

Only the key manager of the token can call this function

Parameters

NameTypeDescription
_recipientaddressthe address that will receive the token ownership
_tokenIduint256the id of the token

unlockProtocol

function unlockProtocol() external view returns (address)

Returns

NameTypeDescription
_0addressundefined

updateKeyPricing

function updateKeyPricing(uint256 _keyPrice, address _tokenAddress) external nonpayable

A function which lets a Lock manager of the lock to change the price for future purchases.

Throws if called by other than a Lock managerThrows if lock has been disabledThrows if _tokenAddress is not a valid token

Parameters

NameTypeDescription
_keyPriceuint256The new price to set for keys
_tokenAddressaddressThe address of the erc20 token to use for pricing the keys, or 0 to use ETH

updateLockConfig

function updateLockConfig(uint256 _newExpirationDuration, uint256 _maxNumberOfKeys, uint256 _maxKeysPerAcccount) external nonpayable

Update the main key properties for the entire lock: - default duration of each key - the maximum number of keys the lock can edit - the maximum number of keys a single address can holdkeys previously bought are unaffected by this changes in expiration duration (i.e. existing keys timestamps are not recalculated/updated)

_maxNumberOfKeys Can't be smaller than the existing supply

Parameters

NameTypeDescription
_newExpirationDurationuint256the new amount of time for each key purchased or type(uint).max for a non-expiring key
_maxNumberOfKeysuint256uint the maximum number of keys
_maxKeysPerAcccountuint256the maximum amount of key a single user can own

updateRefundPenalty

function updateRefundPenalty(uint256 _freeTrialLength, uint256 _refundPenaltyBasisPoints) external nonpayable

Allow a Lock manager to change the refund penalty.

Throws if called by other than a Lock manager

Parameters

NameTypeDescription
_freeTrialLengthuint256The new duration of free trials for this lock
_refundPenaltyBasisPointsuint256The new refund penaly in basis-points(bps)

updateSchemaVersion

function updateSchemaVersion() external nonpayable

Set the schema version to the latestonly lock manager call call this

updateTransferFee

function updateTransferFee(uint256 _transferFeeBasisPoints) external nonpayable

Allow a Lock manager to change the transfer fee.

Throws if called by other than a Lock manager

Parameters

NameTypeDescription
_transferFeeBasisPointsuint256The new transfer fee in basis-points(bps). Ex: 200 bps = 2%

withdraw

function withdraw(address _tokenAddress, address payable _recipient, uint256 _amount) external nonpayable

Called by lock manager to withdraw all funds from the lock

Parameters

NameTypeDescription
_tokenAddressaddressspecifies the token address to withdraw or 0 for ETH. This is usually the same as tokenAddress in MixinFunds.
_recipientaddress payablespecifies the address that will receive the tokens
_amountuint256specifies the max amount to withdraw, which may be reduced when considering the available balance. Set to 0 or MAX_UINT to withdraw everything. -- however be wary of draining funds as it breaks the cancelAndRefund and expireAndRefundFor use cases.