old_contents: import weakref
  import unittest
  import vapoursynth as vs
  
  
  class FilterTestSequence(unittest.TestCase):
  
      def setUp(self):
          self.core = vs.get_core()
  
      def test_weakref_core(self):
          ref = weakref.ref(self.core)
          self.assert_(ref() is self.core)
  
      def test_weakref_node(self):
          video = self.core.std.BlankClip()
          ref = weakref.ref(video)
          self.assert_(ref() is video)
  
      def test_weakref_frame(self):
          video = self.core.std.BlankClip()
          frame = video.get_frame(0)
          ref = weakref.ref(frame)
          self.assert_(ref() is frame)
  
  if __name__ == '__main__':
      unittest.main()
  
new_contents: import weakref
  import unittest
  import vapoursynth as vs
  
  
  class FilterTestSequence(unittest.TestCase):
  
      def setUp(self):
          self.core = vs.get_core()
  
      def test_weakref_core(self):
          ref = weakref.ref(self.core)
          self.assertTrue(ref() is self.core)
  
      def test_weakref_node(self):
          video = self.core.std.BlankClip()
          ref = weakref.ref(video)
          self.assertTrue(ref() is video)
  
      def test_weakref_frame(self):
          video = self.core.std.BlankClip()
          frame = video.get_frame(0)
          ref = weakref.ref(frame)
          self.assertTrue(ref() is frame)
  
  if __name__ == '__main__':
      unittest.main()
  
subject: Fix one more deprecation warning