def test_sliding_window_of_short_iterator():
assert list(sliding_window(3, [1, 2])) == []
def test_sliding_window():
assert list(sliding_window(2, [1, 2, 3, 4])) == [(1, 2), (2, 3), (3, 4)]
assert list(sliding_window(3, [1, 2, 3, 4])) == [(1, 2, 3), (2, 3, 4)]
