improve hello world examples shutdown process

Author: ronenhamias

services-examples/src/main/java/io/scalecube/services/examples/helloworld/Example1.java

@@ -6,6 +6,7 @@
 import io.scalecube.services.examples.helloworld.service.GreetingServiceImpl;
 import io.scalecube.services.examples.helloworld.service.api.GreetingsService;
 import io.scalecube.services.transport.rsocket.RSocketServiceTransport;
+import reactor.core.publisher.Mono;
 
 /**
  * The Hello World project is a time-honored tradition in computer programming. It is a simple
@@ -50,7 +51,6 @@ public static void main(String[] args) {
     // Execute the services and subscribe to service events
     service.sayHello("joe").subscribe(consumer -> System.out.println(consumer.message()));
 
-    seed.onShutdown().block();
-    ms.onShutdown().block();
+    Mono.whenDelayError(seed.shutdown(), ms.shutdown()).block();
   }
 }

services-examples/src/main/java/io/scalecube/services/examples/helloworld/Example2.java

@@ -70,7 +70,6 @@ public static void main(String[] args) {
               System.out.println(greeting.message());
             });
 
-    seed.onShutdown().block();
-    ms.onShutdown().block();
+    Mono.whenDelayError(seed.shutdown(), ms.shutdown()).block();
   }
 }

services-examples/src/main/java/io/scalecube/services/examples/helloworld/Example3.java

@@ -7,6 +7,7 @@
 import io.scalecube.services.examples.helloworld.service.api.BidiGreetingService;
 import io.scalecube.services.transport.rsocket.RSocketServiceTransport;
 import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
 
 /**
  * The Hello World project is a time-honored tradition in computer programming. It is a simple
@@ -54,7 +55,6 @@ public static void main(String[] args) {
         .doOnNext(System.out::println)
         .blockLast();
 
-    seed.onShutdown().block();
-    ms.onShutdown().block();
+    Mono.whenDelayError(seed.shutdown(), ms.shutdown()).block();
   }
 }