def METHOD_NAME(self):
    filter_three = MyFilter()
    self.percolator.removefilter(self.filter_two)
    self.assertEqual(self.percolator.top, self.filter_one)
    self.assertIsNone(self.filter_two.delegate)
    filter_three = MyFilter()
    self.percolator.insertfilter(self.filter_two)
    self.percolator.insertfilter(filter_three)
    self.percolator.removefilter(self.filter_one)
    self.assertEqual(self.percolator.top, filter_three)
    self.assertEqual(filter_three.delegate, self.filter_two)
    self.assertEqual(self.filter_two.delegate, self.percolator.bottom)
    self.assertIsNone(self.filter_one.delegate)