// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/abstractcontractContext{
function_msgSender() internalviewvirtualreturns (address) {
returnmsg.sender;
}
function_msgData() internalviewvirtualreturns (bytescalldata) {
returnmsg.data;
}
}
// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;import"../utils/Context.sol";
/**
* @dev Contract module which allows children to implement an emergency stop
* mechanism that can be triggered by an authorized account.
*
* This module is used through inheritance. It will make available the
* modifiers `whenNotPaused` and `whenPaused`, which can be applied to
* the functions of your contract. Note that they will not be pausable by
* simply including this module, only once the modifiers are put in place.
*/abstractcontractPausableisContext{
/**
* @dev Emitted when the pause is triggered by `account`.
*/eventPaused(address account);
/**
* @dev Emitted when the pause is lifted by `account`.
*/eventUnpaused(address account);
boolprivate _paused;
/**
* @dev Initializes the contract in unpaused state.
*/constructor() {
_paused =false;
}
/**
* @dev Returns true if the contract is paused, and false otherwise.
*/functionpaused() publicviewvirtualreturns (bool) {
return _paused;
}
/**
* @dev Modifier to make a function callable only when the contract is not paused.
*
* Requirements:
*
* - The contract must not be paused.
*/modifierwhenNotPaused() {
require(!paused(), "Pausable: paused");
_;
}
/**
* @dev Modifier to make a function callable only when the contract is paused.
*
* Requirements:
*
* - The contract must be paused.
*/modifierwhenPaused() {
require(paused(), "Pausable: not paused");
_;
}
/**
* @dev Triggers stopped state.
*
* Requirements:
*
* - The contract must not be paused.
*/function_pause() internalvirtualwhenNotPaused{
_paused =true;
emit Paused(_msgSender());
}
/**
* @dev Returns to normal state.
*
* Requirements:
*
* - The contract must be paused.
*/function_unpause() internalvirtualwhenPaused{
_paused =false;
emit Unpaused(_msgSender());
}
}