docs: public static String[] internInPlace(String[] input) {
          if (input == null) {
              return null;
          } else if (input.length == 0) {
              return EMPTY_STRING_ARRAY;
          }
          for (int i=0; i<input.length; i++) {
              input[i] = Util.intern(input[i]);
          }
          return input;
      }