docs: def serialize_break(ctx, document, elem, root):
      "Serialize break element."
  
      if elem.break_type == u'textWrapping':
          _div = etree.SubElement(root, 'br')
      else:
          _div = etree.SubElement(root, 'span')
          if ctx.options['embed_styles']:
              _div.set('style', 'page-break-after: always;')
  
      fire_hooks(ctx, document, elem, _div, ctx.get_hook('page_break'))
  
      return root