code: def findport(self, port):
          
          for p in self.ports:
              if p[0] == p:
                  return p
          p = (port, [])
          self.ports.append(p)
          return p
docs: Find and return a port tuple for the specified port.
          Created and added when not found.
          @param port: A port.
          @type port: I{service.Port}
          @return: A port tuple.
          @rtype: (port, [method])