def METHOD_NAME():
    primitive_instance = ExponentialWeightedVariance(span=1.5)
    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, 0.5, 12.999999999999996, 2.996898263027294])
    pd.testing.assert_series_equal(answer, correct_answer)