Was able to correct by making these changes:
contract Ownable is Context {
// OWNER DATA
address public _owner;
address public _proposedOwner;
address private _oldOwner;
uint256 private _lockTime;
// OWNABLE EVENTS
event OwnershipTransferProposed(
address indexed currentOwner,
address indexed proposedOwner
);
event OwnershipTransferDisregarded(
address indexed oldProposedOwner
);
event OwnershipTransferred(
address indexed oldOwner,
address indexed newOwner
);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor () {
address msgSender = _msgSender();
_owner = msgSender;
emit OwnershipTransferred(address(0), msgSender);
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view returns (address) {
return _owner;
}
/**
* @dev Returns the address of the current owner.
*/
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require(_owner == _msgSender(), "Ownable: caller is not the owner");
_;
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions anymore. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
emit OwnershipTransferred(_owner, address(0));
_owner = address(0);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
emit OwnershipTransferred(_owner, newOwner);
_owner = newOwner;
}
function getUnlockTime() public view returns (uint256) {
return _lockTime;
}
//Locks the contract for owner for the amount of time provided
function lock(uint256 time) public virtual onlyOwner {
_oldOwner = _owner;
_owner = address(0);
_lockTime = block.timestamp + time;
emit OwnershipTransferred(_owner, address(0));
}
//Unlocks the contract for owner when _lockTime is exceeds
function unlock() public virtual {
require(_oldOwner == msg.sender, "You don't have permission to unlock");
require(block.timestamp > _lockTime , "Contract is locked until 7 days");
emit OwnershipTransferred(_owner, _oldOwner);
_owner = _oldOwner;
}
}