def METHOD_NAME(self):
    key = self.table.nextKey()
    assert key == self.keys[0], key
    for i in range(1, len(self.keys)):
        key = self.table.nextKey(key)
        assert key == self.keys[i], key
    # We're at the end, next should be None
    key = self.table.nextKey(key)
    assert key is None, key