code: def strip(parser, arg):
      
      nodelist = parser.parse(('endstrip',))
      parser.delete_first_token()
      return StripNode(nodelist, arg.split_contents())
docs: example:
          {% strip '<br>' %}
              content...
              content...
          {% endstrip %}
      result:
          content...<br>content...
      arg special symbols: {\n} = \n