@Override
    public IntMaximum clone() {
        IntMaximum clone = new IntMaximum();
        clone.max = this.max;
        return clone;
    }
@Test
    void testClone() {
        IntMaximum max = new IntMaximum();
        int value = 42;

        max.add(value);

        IntMaximum clone = max.clone();
        assertThat(clone.getLocalValue().intValue()).isEqualTo(value);
    }