def METHOD_NAME():
    # Check extreme cases work, where either past length or future length is
    # empty.
    assert len(tf.split(0).past) == 0
    assert len(tf.split(len(tf)).future) == 0
    assert len(tf.split(tf.index.start).past) == 0
    assert len(tf.split(tf.index.start + len(tf)).future) == 0
    with pytest.raises(ValueError):
        tf.split(len(tf) + 1)
    with pytest.raises(Exception):
        tf.split(tf.index.start + len(tf) + 1)
    with pytest.raises(ValueError):
        tf.split(-(len(tf) + 1))
    with pytest.raises(Exception):
        tf.split(tf.index.start - 1)