docs: def _from_dict(cls, _dict):
          """Initialize a SupportedFeatures object from a json dictionary."""
          args = {}
          if 'custom_language_model' in _dict:
              args['custom_language_model'] = _dict.get('custom_language_model')
          else:
              raise ValueError(
                  'Required property \'custom_language_model\' not present in SupportedFeatures JSON'
              )
          if 'speaker_labels' in _dict:
              args['speaker_labels'] = _dict.get('speaker_labels')
          else:
              raise ValueError(
                  'Required property \'speaker_labels\' not present in SupportedFeatures JSON'
              )
          return cls(**args)