docs: def _to_dict(self):
          """Return a json dictionary representing this model."""
          _dict = {}
          if hasattr(self, 'debug') and self.debug is not None:
              _dict['debug'] = self.debug
          if hasattr(self, 'restart') and self.restart is not None:
              _dict['restart'] = self.restart
          if hasattr(self,
                     'alternate_intents') and self.alternate_intents is not None:
              _dict['alternate_intents'] = self.alternate_intents
          if hasattr(self, 'return_context') and self.return_context is not None:
              _dict['return_context'] = self.return_context
          return _dict