code: def fulfill(self, agreement_id, message, account_address, signature, from_account):
          
          return self._fulfill(
              agreement_id,
              message,
              account_address,
              signature,
              transact={'from': from_account.address,
                        'passphrase': from_account.password}
          )
docs: Fulfill the sign conditon.
  
          :param agreement_id: id of the agreement, hex str
          :param message:
          :param account_address: ethereum account address, hex str
          :param signature: signed agreement hash, hex str
          :param from_account: Account doing the transaction
          :return: