docs: def _from_dict(cls, _dict):
          """Initialize a RelationArgument object from a json dictionary."""
          args = {}
          if 'entities' in _dict:
              args['entities'] = [
                  RelationEntity._from_dict(x) for x in (_dict.get('entities'))
              ]
          if 'location' in _dict:
              args['location'] = _dict.get('location')
          if 'text' in _dict:
              args['text'] = _dict.get('text')
          return cls(**args)