void () { StringJoiner stringJoiner1 = new StringJoiner(",", "(", ")"); System.out.println(stringJoiner1.toString()); StringJoiner <warning descr="Contents of 'StringJoiner stringJoiner2' are queried, but never updated">stringJoiner2</warning> = new StringJoiner(","); //warn System.out.println(stringJoiner2.toString()); StringJoiner <warning descr="Contents of 'StringJoiner stringJoiner3' are updated, but never queried">stringJoiner3</warning> = new StringJoiner(","); //warn stringJoiner3.add("1").add("1"); StringJoiner stringJoiner4 = new StringJoiner(","); StringJoiner <warning descr="Contents of 'StringJoiner stringJoiner5' are updated, but never queried">stringJoiner5</warning> = new StringJoiner(","); //warn stringJoiner5.merge(stringJoiner4); stringJoiner5.add("1"); }