import tensorflow as tf

      scope: optional name scope for summary tags.

  Returns:
      a scalar tensor representing the correlation loss value.
  """
  with tf.name_scope(name):
    source_samples -= tf.reduce_mean(source_samples, 0)
    target_samples -= tf.reduce_mean(target_samples, 0)
    source_samples = tf.nn.l2_normalize(source_samples, 1)
    target_samples = tf.nn.l2_normalize(target_samples, 1)
