    def test_sliding_small(self):
        """
        size > step

        Inputs:

          ----1-2-3-4-5-6-7-8-9--->

        size: 3
        step: 2

        outputs:
          ----[1, 2, 3] - [3, 4, 5] - [5, 6, 7] - [7, 8, 9] - [9] ---->
        """
        ret = [[1, 2, 3], [3, 4, 5], [5, 6, 7], [7, 8, 9], [9]]
        index = 0
        buf = _WindowBuffer(3, 2)
        for i in range(1, 10):
            if buf(i, i - 1):
                self.assertEqual(buf.data, ret[index])
                index += 1
                buf = buf.next()

        while buf is not None:
            if buf.data:
                self.assertEqual(buf.data, ret[index])
                index += 1
            buf = buf.next()
size > step

Inputs:

----1-2-3-4-5-6-7-8-9--->

size: 3
step: 2

outputs:
----[1, 2, 3] - [3, 4, 5] - [5, 6, 7] - [7, 8, 9] - [9] ---->
tests/unittests/runtime/test_window_node.py