old_contents: from django.template import Library, Node
  
  register = Library()
  
  @register.tag(name="sneak_peek")
  def sneak_peek(parser, token):
      tag = None
      style = 'default'
      try:
          tag, style = token.split_contents()
      except ValueError:
          pass
      nodelist = parser.parse(('endsneak_peek',))
      parser.delete_first_token()
      return SneakPeekWrapper(nodelist, style)
  
  
  class SneakPeekWrapper(Node):
      def __init__(self, nodelist, style):
          self.nodelist = nodelist
          self.style = style
  
      def render(self, context):
          user = context['user']
          user_is_blessed = user.has_perm('sneak_peek_tag.can_view_sneak_peek')
  
          if user_is_blessed:
              content = self.nodelist.render(context)
              wrapped_hidden_feature = """<div class="django-sneak-peek %s">
                  	%s
                  </div>""" % (self.style, content)
              return wrapped_hidden_feature
          else:
              return ''
  
new_contents: from django.template import Library, Node
  
  register = Library()
  
  @register.tag(name="sneak_peek")
  def sneak_peek(parser, token):
      tag = None
      style = 'default'
      try:
          tag, style = token.split_contents()
      except ValueError:
          pass
      if not (style[0] == style[-1] and style[0] in ('"', "'")):
          raise template.TemplateSyntaxError("%r tag's argument should be in quotes" % tag)
      nodelist = parser.parse(('endsneak_peek',))
      parser.delete_first_token()
      return SneakPeekWrapper(nodelist, style[1:-1])
  
  
  class SneakPeekWrapper(Node):
      def __init__(self, nodelist, style):
          self.nodelist = nodelist
          self.style = style
  
      def render(self, context):
          user = context['user']
          user_is_blessed = user.has_perm('sneak_peek_tag.can_view_sneak_peek')
  
          if user_is_blessed:
              content = self.nodelist.render(context)
              wrapped_hidden_feature = """<div class="django-sneak-peek %s">
                  	%s
                  </div>""" % (self.style, content)
              return wrapped_hidden_feature
          else:
              return ''
  
subject: change first arg to use quotes