def test_order(self):
        assert (event.Priority.PRE_CORE
                > event.Priority.CORE
                > event.Priority.POST_CORE
                > event.Priority.PRE_DEFAULT
                > event.Priority.DEFAULT
                > event.Priority.POST_DEFAULT)
def test_impl():
            A = np.array([1., 2., 3.])
            A[0] = np.nan
            df = pd.DataFrame({'A': A})
            B = df.A.fillna(5.0)
            return B.sum()