def create_anonymous_boxes(box):
    """Create anonymous boxes in box descendants according to layout rules."""
    box = anonymous_table_boxes(box)
    box = flex_boxes(box)
    box = grid_boxes(box)
    box = inline_in_block(box)
    box = block_in_inline(box)
    return box
Create anonymous boxes in box descendants according to layout rules.
weasyprint/formatting_structure/build.py