old_contents: 
  from __future__ import (
      absolute_import, division, print_function, unicode_literals
  )
  
  from klein.plating import Plating
  from twisted.web.template import tags, slot
  
  from klein.test.test_resource import requestMock, _render
  from klein.test.util import TestCase
  from klein import Klein
  
  plating = Plating(
      dict(
          title="JUST A TITLE",
          content="NEVER MIND THE CONTENT",
      ),
      tags=tags.html(
          tags.head(tags.title(slot("title"))),
          tags.body(
              tags.h1(slot("title")),
              tags.div(slot("content"),
                       Class="content")
          )
      ),
  )
  
  
  class PlatingTests(TestCase):
      """
      Tests for L{Plating}.
      """
  
      def setUp(self):
          """
          Create an app and a resource wrapping that app for this test.
          """
          self.app = Klein()
          self.kr = self.app.resource()
  
  
      def test_template(self):
          """
          Rendering a L{Plating.content} decorated route results in stuff.
          """
  
          @self.app.route("/")
          @plating.content(tags.span(slot("ok")))
          def plateMe(request):
              return {"ok": "test-data-present"}
  
          request = requestMock(b"/")
          d = _render(self.kr, request)
          self.successResultOf(d)
          self.assertIn(b'test-data-present', request.getWrittenData())
  
new_contents: 
  from __future__ import (
      absolute_import, division, print_function, unicode_literals
  )
  
  from klein.plating import Plating
  from twisted.web.template import tags, slot
  
  from klein.test.test_resource import requestMock, _render
  from klein.test.util import TestCase
  from klein import Klein
  
  plating = Plating(
      dict(
          title="JUST A TITLE",
          content="NEVER MIND THE CONTENT",
      ),
      tags=tags.html(
          tags.head(tags.title(slot("title"))),
          tags.body(
              tags.h1(slot("title")),
              tags.div(slot("content"),
                       Class="content")
          )
      ),
  )
  
  
  class PlatingTests(TestCase):
      """
      Tests for L{Plating}.
      """
  
      def setUp(self):
          """
          Create an app and a resource wrapping that app for this test.
          """
          self.app = Klein()
          self.kr = self.app.resource()
  
  
      def test_template(self):
          """
          Rendering a L{Plating.content} decorated route results in stuff.
          """
  
          @self.app.route("/")
          @plating.content(tags.span(slot("ok")))
          def plateMe(request):
              return {"ok": "test-data-present"}
  
          request = requestMock(b"/")
          d = _render(self.kr, request)
          self.successResultOf(d)
          self.assertIn(b'<span>test-data-present</span>',
                        request.getWrittenData())
  
subject: fix the test so that it fails.