code: public static String valueOf(int[]source){
          // TODO: Investigate why this method is not on UTF16 class
          StringBuilder result = new StringBuilder(source.length);
          for(int i=0; i<source.length; i++){
              result.appendCodePoint(source[i]);
          }
          return result.toString();
      }
docs: Utility method to take a int[] containing codepoints and return
  a string representation with code units.