@Test
public void testTostring() {

    TagSet raw = new TagSet(new TreeMap<String, Tag>());
    TagSet tagSet1 = raw.add("k1", "v1");
    //覆盖掉v1
    tagSet1 = tagSet1.addAll(new String[] { "k2", "v2", "k1", "v3" });
    System.out.println(tagSet1.toString());
    Assert.assertTrue(tagSet1.toString().contains("k1=v3"));
}