import tensorflow as tf

    For the scale (gamma), a ones initializer is used by default.

    Args:
      var_name: name of variable as a string.
    """
    if var_name not in self._initializers:
      if var_name == self.GAMMA:
        self._initializers[self.GAMMA] = tf.ones_initializer()
      elif var_name == self.BETA:
        self._initializers[self.BETA] = tf.zeros_initializer()

  def _build_statistics_variance(self, input_batch,
                                 reduction_indices, use_batch_stats):
    """Builds the statistics part of the graph when using moving variance.
