import tensorflow as tf

    self.top_layer = bn
    return bn


def loss_function(logits, labels):
  # global cross_entropy # HACK TESTING
  cross_entropy = tf.nn.sparse_softmax_cross_entropy_with_logits(
      logits=logits, labels=labels, name='xentropy')
  loss = tf.reduce_mean(cross_entropy, name='xentropy_mean')
  return loss


