How to use the weasyprint.formatting_structure.boxes.BlockBox.anonymous_from function in weasyprint

new_children = []
    changed = False

    for child in box.children:
        if isinstance(child, boxes.LineBox):
            assert len(box.children) == 1, (
                'Line boxes should have no '
                'siblings at this stage, got %r.' % box.children)
            stack = None
            while 1:
                new_line, block, stack = _inner_block_in_inline(
                    child, skip_stack=stack)
                if block is None:
                    break
                anon = boxes.BlockBox.anonymous_from(box, [new_line])
                new_children.append(anon)
                new_children.append(block_in_inline(block))
                # Loop with the same child and the new stack.
            if new_children:
                # Some children were already added, this became a block
                # context.
                new_child = boxes.BlockBox.anonymous_from(box, [new_line])
            else:
                # Keep the single line box as-is, without anonymous blocks.
                new_child = new_line
        else:
            # Not in an inline formatting context.
            new_child = block_in_inline(child)

        if new_child is not child:
            changed = True

'Line boxes should have no '
                'siblings at this stage, got %r.' % box.children)
            stack = None
            while 1:
                new_line, block, stack = _inner_block_in_inline(
                    child, skip_stack=stack)
                if block is None:
                    break
                anon = boxes.BlockBox.anonymous_from(box, [new_line])
                new_children.append(anon)
                new_children.append(block_in_inline(block))
                # Loop with the same child and the new stack.
            if new_children:
                # Some children were already added, this became a block
                # context.
                new_child = boxes.BlockBox.anonymous_from(box, [new_line])
            else:
                # Keep the single line box as-is, without anonymous blocks.
                new_child = new_line
        else:
            # Not in an inline formatting context.
            new_child = block_in_inline(child)

        if new_child is not child:
            changed = True
        new_children.append(new_child)

    if changed:
        box.children = new_children
    return box

'normal', 'nowrap', 'pre-line')):
                new_line_children.append(child_box)
        else:
            if new_line_children:
                # Inlines are consecutive no more: add this line box
                # and create a new one.
                line_box = boxes.LineBox.anonymous_from(box, new_line_children)
                anonymous = boxes.BlockBox.anonymous_from(box, [line_box])
                new_children.append(anonymous)
                new_line_children = []
            new_children.append(child_box)
    if new_line_children:
        # There were inlines at the end
        line_box = boxes.LineBox.anonymous_from(box, new_line_children)
        if new_children:
            anonymous = boxes.BlockBox.anonymous_from(box, [line_box])
            new_children.append(anonymous)
        else:
            # Only inline-level children: one line box
            new_children.append(line_box)

    box.children = new_children
    return box