Loom example for medium article

Loom.java

import jdk.incubator.concurrent.StructuredTaskScope;

// java --enable-preview --source 19 --add-modules jdk.incubator.concurrent Loom.java
public class Loom {
  public static void main(String[] args) {
      run();
  }

  public static void run() {

    // Simple virtual thread
    Thread.startVirtualThread(() -> System.out.println("Hello from virtual thread"));
    System.out.println("Hello from main thread");

    // Structured concurrency
    try (var scope = new StructuredTaskScope.ShutdownOnFailure()) {
      var aFuture = scope.fork(() -> {
        System.out.println("Hello from structured scope thread 1");
        return 1;
      });

      var bFuture = scope.fork(() -> {
        System.out.println("Hello from structured scope thread 2");
        return 2;
      });

      scope.join();
      scope.throwIfFailed();
      
      System.out.println("Hello from main thread");
      // Integer result =  scope.result(e -> new RuntimeException(e));
      var a = aFuture.resultNow();
      var b = bFuture.resultNow();
      System.out.println("a = " + a + ". b = " + b);
    }
    catch (Exception e) {
      e.printStackTrace();
    }
    
  }
}