def METHOD_NAME():
    vi = VariantInfo([(1, 0), (2, 0)])
    assert vi.get_phasable() == []
    vi.append("A", "C", 1, 0)
    vi.append("A", "G", 1, 1)
    vi.append("C", "A", 2, 0)
    vi.append("C", "G", 1, 0)
    assert vi.get_node_positions() == [0, 2, 2, 3]
    vi.correct_type(0, 2, 0)
    assert vi.get_node_positions() == [0, 0, 2, 2, 3]
    vi.correct_type(3, 0, 0)
    assert vi.get_node_positions() == [0, 0, 2, 2]