def METHOD_NAME():
    primitive_instance = ExponentialWeightedSTD(alpha=0.8)
    primitive_func = primitive_instance.get_function()
    array = pd.Series([1, 2, 7, 5])
    answer = pd.Series(primitive_func(array))
    correct_answer = pd.Series(
        [np.nan, 0.7071067811865476, 3.6055512754639887, 1.7311551816712718],
    )
    pd.testing.assert_series_equal(answer, correct_answer)