@Override
    public BooleanPredicate clone() throws CloneNotSupportedException {
        return (BooleanPredicate)super.clone();
    }
@Test
    void requireThatCloneIsImplemented() throws CloneNotSupportedException {
        BooleanPredicate node1 = new BooleanPredicate(true);
        BooleanPredicate node2 = node1.clone();
        assertEquals(node1, node2);
        assertNotSame(node1, node2);
    }