Method test

streams/OptionalFlatMap.java:14–24

(String descr,
    Function<String, Optional<String>> func)

    return Arrays.stream(elements);
  }
  static void test(String descr,
    Function<String, Optional<String>> func) {
    System.out.println(" ---( " + descr + " )---");
    for(int i = 0; i <= elements.length; i++) {
      System.out.println(
        testStream()
          .skip(i)
          .findFirst()
          .flatMap(func));
    }
  }
  public static void main(String[] args) {

    test("Add brackets",