@Override
    public DoubleMinimum clone() {
        DoubleMinimum clone = new DoubleMinimum();
        clone.min = this.min;
        return clone;
    }
@Test
    void testClone() {
        DoubleMinimum min = new DoubleMinimum();
        double value = 3.14159265359;

        min.add(value);

        DoubleMinimum clone = min.clone();
        assertThat(clone.getLocalValue()).isCloseTo(value, within(0.0));
    }