:param x: A symbolic representation (Tensor) of the network input
    :return: A symbolic representation (Tensor) of the output logits
    (i.e., the values fed as inputs to the softmax layer).

def get_logits(self, x, **kwargs):
    """
    :param x: A symbolic representation (Tensor) of the network input
    :return: A symbolic representation (Tensor) of the output logits
    (i.e., the values fed as inputs to the softmax layer).
    """
    outputs = self.fprop(x, **kwargs)
    if self.O_LOGITS in outputs:
      return outputs[self.O_LOGITS]
    raise NotImplementedError(str(type(self)) + "must implement `get_logits`"
                              " or must define a " + self.O_LOGITS +
                              " output in `fprop`")