@Test
public void testContains() {

        IntegerUnion mergeTool = new IntegerUnion(0, 50);
        mergeTool.remove(25);
        mergeTool.remove(26);
        mergeTool.remove(27);
        
        Assert.assertFalse(mergeTool.contains(26));
        Assert.assertFalse(mergeTool.contains(25));
        Assert.assertFalse(mergeTool.contains(27));
        
        Assert.assertTrue(mergeTool.contains(24));
        Assert.assertTrue(mergeTool.contains(28));
        Assert.assertTrue(mergeTool.contains(0));
        Assert.assertTrue(mergeTool.contains(50));
}