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