code: def get_model_url_base():
      '''
      Returns a root folder for models.
      '''
      url_base = get_model_url_base_from_env()
      if url_base is not None:
          logger.info('NNBLA_MODELS_URL_BASE is set as {}.'.format(url_base))
      else:
          url_base = 'https://nnabla.org/pretrained-models/nnp_models/'
      return url_basf get_model_url_base():
      '''
      Returns a root folder for models.
      '''
      url_base = get_model_url_base_from_env()
      if url_base is not None:
          logger.info('NNBLA_MODELS_URL_BASE is set as {}.'.format(url_base))
      else:
          url_base = 'https://nnabla.org/pretrained-models/nnp_models/'
      return url_base
docs: Returns a root folder for models.