code: def send_async(self, transaction, headers=None):
          
          return self.transport.forward_request(
              method='POST',
              path=self.path,
              json=transaction,
              params={'mode': 'async'},
              headers=headers)
docs: Submit a transaction to the Federation with the mode `async`.
  
          Args:
              transaction (dict): the transaction to be sent
                  to the Federation node(s).
              headers (dict): Optional headers to pass to the request.
  
          Returns:
              dict: The transaction sent to the Federation node(s).