docs: def _find_image_bounding_boxes(filenames, image_to_bboxes):
    """Find the bounding boxes for a given image file.
  
    Args:
      filenames: list of strings; each string is a path to an image file.
      image_to_bboxes: dictionary mapping image file names to a list of
        bounding boxes. This list contains 0+ bounding boxes.
    Returns:
      List of bounding boxes for each image. Note that each entry in this
      list might contain from 0+ entries corresponding to the number of bounding
      box annotations for the image.
    """
    num_image_bbox = 0
    bboxes = []
    for f in filenames:
      basename = os.path.basename(f)
      if basename in image_to_bboxes:
        bboxes.append(image_to_bboxes[basename])
        num_image_bbox += 1
      else:
        bboxes.append([])
    print('Found %d images with bboxes out of %d images' % (
        num_image_bbox, len(filenames)))
    return bboxes