code: def add_loss(self, loss, name=None, regularization=False, add_summaries=True):
      
      # TODO(eiderman): Strip name out and just rely on the name scope.
      _ = name  # Eliminates pylint warning.
      if regularization:
        self._g.add_to_collection(GraphKeys.REGULARIZATION_LOSSES, loss)
  
      tf.add_to_collection(GraphKeys.LOSSES, loss)
      if add_summaries:
        self.add_scalar_summary(loss, 'loss')
        self.add_average_summary(loss, 'loss_average')
docs: Append a loss to the total loss for the network.
  
      Args:
        loss: append this loss operation
        name: The name for this loss, defaults to loss.op.name
        regularization: Set to True if this is a regularization loss.
        add_summaries: Set to True if you want to see scalar and average summary.