def METHOD_NAME():
    p = [1, 0, 0, 0]
    q = [0.9, 0.1, 0, 0]
    assert statistical.perplexity(p, q)[0] == pytest.approx(0.9)
    p = [0.25, 0.25, 0.25, 0.25]
    assert statistical.perplexity(p, q)[0] == pytest.approx(2.190890229752889e-05)