docs: public static boolean containsAnyOf( String str,
                                           char... chars ) {
          CharacterIterator iter = new StringCharacterIterator(str);
          for (char c = iter.first(); c != CharacterIterator.DONE; c = iter.next()) {
              for (char match : chars) {
                  if (c == match) return true;
              }
          }
          return false;
      }