@Test
public void checkNotNull_valid() {

    String data = "string";
    String sameAsData = Utils.checkNotNull(data, "data == null");
    // both of them should be equals by both value and both reference
    assertEquals(data, sameAsData);
    Object o1 = Arrays.asList(1, 2, 3);
    Object sameAsO1 = Utils.checkNotNull(o1, "o1 == null");
    assertEquals(o1, sameAsO1);
}