code: def hparams(self, defaults, unused_model_hparams):
      
      (super(BabiQa, self).hparams(defaults, unused_model_hparams))
      p = defaults
      num_classes = self._encoders["targets"].vocab_size
      p.modality = {"targets": modalities.ModalityType.CLASS_LABEL}
      p.vocab_size = {"targets": num_classes}
docs: Returns problem_hparams.
  
      Args:
        defaults: default hyperparameters
        unused_model_hparams: model hyperparameters