def test_before_after_sort_3(self):
        actual = before_after_sort([ TestItem(1) ])
        desired = [ TestItem(1) ]
        self.assertEquals(actual, desired)
Does the degenerate case for the before-after sort work?
dataset/ETHPy150Open enthought/pyface/pyface/tasks/tests/test_topological_sort.py/TopologicalSortTestCase.test_before_after_sort_3