docs: def view_modifier(parser, token):
      """
      Output view modifier.
      """
      try:
          tag_name, view_modifier = token.split_contents()
      except ValueError:
          raise template.TemplateSyntaxError('view_modifier tag requires 1 argument (view_modifier), %s given' % (len(token.split_contents()) - 1))
      return ViewModifierNode(view_modifier)