code: def call(self, rs, name, user, fields):
          
          # Call the dynamic method.
          if name not in self._objects:
              return '[ERR: Object Not Found]'
          func = self._objects[name]
          reply = ''
          try:
              reply = func(rs, fields)
              if reply is None:
                  reply = ''
          except Exception as e:
              raise PythonObjectError("Error executing Python object: " + str(e))
          return text_type(reply)
docs: Invoke a previously loaded object.
  
          :param RiveScript rs: the parent RiveScript instance.
          :param str name: The name of the object macro to be called.
          :param str user: The user ID invoking the object macro.
          :param []str fields: Array of words sent as the object's arguments.
  
          :return str: The output of the object macro.