Class CustomSequence

Lib/test/test_collections.py:1593–1599

    def test_issue26915(self):
        # Container membership test should check identity first
        class CustomSequence(Sequence):
            def __init__(self, seq):
                self._seq = seq
            def __getitem__(self, index):
                return self._seq[index]
            def __len__(self):
                return len(self._seq)

        nan = float('nan')
        obj = support.NEVER_EQ