code: def l1_regression_loss(y, target, name=None):
    
    with tf.name_scope(name, 'l1_regression', [y, target]) as scope:
      y = tf.convert_to_tensor(y, name='y')
      target = tf.convert_to_tensor(target, name='target')
      return reduce_batch_sum(tf.abs(y - target), name=scope)
docs: Calculates the sum of absolute errors between y and target.
  
    Args:
      y: the calculated values.
      target: the desired values.
      name: the name for this op, defaults to l1_regression
    Returns:
      A tensorflow op.