docs: def _caller(self, iface_name, func_name):
          """
          Returns a function for the given interface and function name.  When invoked it
          calls client.call() with the correct arguments.
          
          :Parameters:
            iface_name
              Name of interface to call when invoked
            func_name
              Name of function to call when invoked
            params
              Params pass to function from the calling application
          """
          def caller(*params):
              return self.client.call(iface_name, func_name, params)
          return caller