@Test
public void testAdd() {

        IntegerUnion mergeTool = new IntegerUnion(15, 50);
        Assert.assertTrue(mergeTool.add(51));
        check(mergeTool, new Integer[]{15, 51});
        Assert.assertTrue(mergeTool.add(14));
        check(mergeTool, new Integer[]{14, 51});
        Assert.assertTrue(mergeTool.add(53));
        check(mergeTool, new Integer[]{14, 51, 53, 53});
        Assert.assertTrue(mergeTool.add(52));
        check(mergeTool, new Integer[]{14, 53});
        Assert.assertFalse(mergeTool.add(14));
        check(mergeTool, new Integer[]{14, 53});
        Assert.assertFalse(mergeTool.add(53));
        check(mergeTool, new Integer[]{14, 53});
        Assert.assertFalse(mergeTool.add(15));
        Assert.assertFalse(mergeTool.add(52));
        check(mergeTool, new Integer[]{14, 53});
        Assert.assertTrue(mergeTool.add(12));
        check(mergeTool, new Integer[]{12, 12, 14, 53});
}