code: def abort(self, reason):
          
          if _debug: ClientSSM._debug("abort %r", reason)
  
          # change the state to aborted
          self.set_state(ABORTED)
  
          # build an abort PDU to return
          abort_pdu = AbortPDU(False, self.invokeID, reason)
  
          # return it
          return abort_pdu
docs: This function is called when the transaction should be aborted.