code: def get_matching_multiplex_port(self,name):
          
  
          # short circuit:  if the attribute name already exists return none
          # if name in self._portnames: return None
          # if not len([p for p in self._portnames if name.startswith(p) and name != p]): return None
  
          matching_multiplex_ports = [self.__getattribute__(p) for p in self._portnames
              if name.startswith(p)
              and name != p
              and hasattr(self, p)
              and self.__getattribute__(p).is_multiplex
          ]
  
          for port in matching_multiplex_ports:
              return port
  
          return None
docs: Given a name, figure out if a multiplex port prefixes this name and return it.  Otherwise return none.