@Override
    public void merge(Accumulator<Long, Long> other) {
        this.max = Math.max(this.max, other.getLocalValue());
    }
@Test
    void testMerge() {
        LongMaximum max1 = new LongMaximum();
        max1.add(1234567890987654321L);

        LongMaximum max2 = new LongMaximum();
        max2.add(5678909876543210123L);

        max2.merge(max1);
        assertThat(max2.getLocalValue().longValue()).isEqualTo(5678909876543210123L);

        max1.merge(max2);
        assertThat(max1.getLocalValue().longValue()).isEqualTo(5678909876543210123L);
    }