Method orElseThrow

streams/Optionals.java:26–33

(Optional<String> optString)

      optString.orElseGet(() -> "Generated"));
  }
  static void orElseThrow(Optional<String> optString) {
    try {
      System.out.println(optString.orElseThrow(
        () -> new Exception("Supplied")));
    } catch(Exception e) {
      System.out.println("Caught " + e);
    }
  }
  static void test(String testName,
    Consumer<Optional<String>> cos) {
    System.out.println(" === " + testName + " === ");