@Test
public void testAppend() {

    t1.append("");
    assertEquals("add empty string", name, t1.toString());
    t1.append("Smith");
    name += (" " + "Smith");
    assertEquals("append simple string", name, t1.toString());
    t1.append(",", "");
    assertEquals("append empty string with delimiter", name, t1.toString());
    t1.append(",", null);
    assertEquals("append null with delimiter", name, t1.toString());
    t1.append(",", "Xyz Ltd.");
    name += (", " + "Xyz Ltd.");
    assertEquals("append string with delimiter", name, t1.toString());
}