text: c_uuid = None
  
  def store_c_uuid():
      global c_uuid
      c_uuid = next(iter(reality.resources_by_logical_name('C')))
  
  def check_c_replaced():
      test.assertNotEqual(c_uuid,
                          next(iter(reality.resources_by_logical_name('newC'))))
      test.assertIsNot(c_uuid, None)
  
  
  example_template = Template({
      'A': RsrcDef({'a': 'initial'}, []),
      'B': RsrcDef({}, []),
      'C': RsrcDef({'!a': GetAtt('A', 'a')}, ['B']),
      'D': RsrcDef({'c': GetRes('C')}, []),
      'E': RsrcDef({'ca': GetAtt('C', '!a')}, []),
  })
  engine.create_stack('foo', example_template)
  engine.noop(5)
  engine.call(verify, example_template)
  engine.call(store_c_uuid)
  
  example_template_updated = Template({
      'A': RsrcDef({'a': 'updated'}, []),
      'B': RsrcDef({}, []),
      'newC': RsrcDef({'!a': GetAtt('A', 'a')}, ['B']),
      'D': RsrcDef({'c': GetRes('newC')}, []),
      'E': RsrcDef({'ca': GetAtt('newC', '!a')}, []),
  })
  engine.update_stack('foo', example_template_updated)
  engine.noop(11)
  engine.call(verify, example_template_updated)
  
  example_template_long = Template({
      'A': RsrcDef({'a': 'updated'}, []),
      'B': RsrcDef({}, []),
      'newC': RsrcDef({'!a': GetAtt('A', 'a')}, ['B']),
      'D': RsrcDef({'c': GetRes('newC')}, []),
      'E': RsrcDef({'ca': GetAtt('newC', '!a')}, []),
      'F': RsrcDef({}, ['D', 'E']),
  })
  engine.update_stack('foo', example_template_long)
  engine.noop(12)
  engine.call(verify, example_template_long)
  engine.call(check_c_replaced)
  
  engine.delete_stack('foo')
  engine.noop(6)
  engine.call(verify, Template({}))
  