old_contents: import tests
  
  class CallbackTests(tests.TestCase):
      def test_hello_world(self):
          result = []
  
          def hello_world(loop):
              result.append('Hello World')
              loop.stop()
  
          self.loop.call_soon(hello_world, self.loop)
          self.loop.run_forever()
          self.assertEqual(result, ['Hello World'])
  
      def test_soon_stop_soon(self):
          result = []
  
          def hello():
              result.append("Hello")
  
          def world():
              result.append("World")
              self.loop.stop()
  
          self.loop.call_soon(hello)
          self.loop.stop()
          self.loop.call_soon(world)
  
          self.loop.run_forever()
          self.assertEqual(result, ["Hello"])
  
          self.loop.run_forever()
          self.assertEqual(result, ["Hello", "World"])
  
      def test_close_soon(self):
          def func():
              pass
  
          self.loop.close()
          # FIXME: calling call_soon() on a closed event loop should raise an
          # exception:
          # http://bugs.python.org/issue22922
          self.loop.call_soon(func)
  
  
  if __name__ == '__main__':
      import unittest
      unittest.main()
  
new_contents: import tests
  
  class CallbackTests(tests.TestCase):
      def test_hello_world(self):
          result = []
  
          def hello_world(loop):
              result.append('Hello World')
              loop.stop()
  
          self.loop.call_soon(hello_world, self.loop)
          self.loop.run_forever()
          self.assertEqual(result, ['Hello World'])
  
      def test_soon_stop_soon(self):
          result = []
  
          def hello():
              result.append("Hello")
  
          def world():
              result.append("World")
              self.loop.stop()
  
          self.loop.call_soon(hello)
          self.loop.stop()
          self.loop.call_soon(world)
  
          self.loop.run_forever()
          self.assertEqual(result, ["Hello"])
  
          self.loop.run_forever()
          self.assertEqual(result, ["Hello", "World"])
  
  
  if __name__ == '__main__':
      import unittest
      unittest.main()
  
subject: Remove a test which behaves differently depending on the the version of asyncio/trollius