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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def unlock(self, password: str):
 """Unlock the account with a password. If the account is already unlocked, nothing happens, even if the password is wrong. Raises: ValueError: (originating in ethereum.keys) if the password is wrong (and the account is locked) """

        if self.locked:
            self._privkey = decode_keyfile_json(self.keystore, password.encode('UTF-8'))
            self.locked = False
            # get address such that it stays accessible after a subsequent lock
            self._fill_address()