def __init__(
      self, response: str = 'Quick brown fox jumps over a lazy dog'
  ) -> None:
    """Initializes the instance.

    Args:
      response: string that the model returns when sampling text
    """
    self._response = response
Initializes the instance.

    Args:
      response: string that the model returns when sampling text
    
concordia/testing/mock_model.py