code: def performable(parser, token):
      
      bits = token.split_contents()
      if len(bits) > 1:
          raise TemplateSyntaxError("'%s' takes no arguments" % bits[0])
      return PerformableNode()
docs: Performable template tag.
  
      Renders Javascript code to set-up Performable tracking.  You must
      supply your Performable API key in the ``PERFORMABLE_API_KEY``
      setting.