code: def drop(self):
          
          self._request_queue.put(
              requests.DropRequest(ack_id=self._ack_id, byte_size=self.size)
          )
docs: Release the message from lease management.
  
          This informs the policy to no longer hold on to the lease for this
          message. Pub/Sub will re-deliver the message if it is not acknowledged
          before the existing lease expires.
  
          .. warning::
              For most use cases, the only reason to drop a message from
              lease management is on :meth:`ack` or :meth:`nack`; these methods
              both call this one. You probably do not want to call this method
              directly.