code: def _to_dict(self):
          
          _dict = {}
          if hasattr(self, 'text') and self.text is not None:
              _dict['text'] = self.text
          if hasattr(self, 'type') and self.type is not None:
              _dict['type'] = self.type
          if hasattr(self, 'evidence') and self.evidence is not None:
              _dict['evidence'] = [x._to_dict() for x in self.evidence]
          return _dict
docs: Return a json dictionary representing this model.