message: Add a newline before the doctest and indent it at the same level.
diff: @@ -851,6 +851,7 @@ def pad_to_bounding_box(image, offset_height, offset_width, target_height,
  `target_height` by `target_width`.
  Usage Example:
  +
  >>> x = [[[1., 2., 3.],
  ... [4., 5., 6.]],
  ... [[7., 8., 9.],
  