@Override
    protected boolean isNan(Long number) {
        // NaN never applies here because only types like Float and Double have NaN
        return false;
    }
@Test
    void testIsNan() {
        LongSummaryAggregator ag = new LongSummaryAggregator();
        // always false for Long
        assertThat(ag.isNan(-1L)).isFalse();
        assertThat(ag.isNan(0L)).isFalse();
        assertThat(ag.isNan(23L)).isFalse();
        assertThat(ag.isNan(Long.MAX_VALUE)).isFalse();
        assertThat(ag.isNan(Long.MIN_VALUE)).isFalse();
        assertThat(ag.isNan(null)).isFalse();
    }