@Test
public void testCurrent() {

    CMLStack stack = new CMLStack();
    stack.push("first");
    Assert.assertEquals("first", stack.current());
    stack.push("second");
    Assert.assertEquals("second", stack.current());
    stack.push("third");
    Assert.assertEquals("third", stack.current());
    stack.pop();
    Assert.assertEquals("second", stack.current());
    stack.pop();
    Assert.assertEquals("first", stack.current());
}