from tensorflow.contrib.learn.python.learn.estimators import tensor_signature

    Expected to be overriden by sub-classes that require custom support.
    This implementation uses `model_fn` passed as parameter to constructor to
    build model.

    Args:
      features: `Tensor` or `dict` of `Tensor` objects.

    Returns:
      predictions: `Tensor` or `dict` of `Tensor` objects.
    """
    targets = tensor_signature.create_placeholders_from_signatures(
        self._targets_info)
    predictions, _ = self._model_fn(features, targets, ModeKeys.INFER)
    return predictions

  def _get_default_metric_functions(self):
    """Method that provides default metric operations.

    Returns:
      a dictionary of metric operations.
