Merge pull request ReactiveX#508 from benjchristensen/empty-subscribe

Empty subscribe

Author: benjchristensen

rxjava-core/src/main/java/rx/Observable.java

@@ -303,6 +303,33 @@ private Subscription protectivelyWrapAndSubscribe(Observer<? super T> o) {
         return subscription.wrap(subscribe(new SafeObserver<T>(subscription, o)));
     }
 
+    /**
+     * Subscribe and ignore all events.
+     *  
+     * @return 
+     */
+    public Subscription subscribe() {
+        return protectivelyWrapAndSubscribe(new Observer<T>() {
+
+            @Override
+            public void onCompleted() {
+                // do nothing
+            }
+
+            @Override
+            public void onError(Throwable e) {
+                handleError(e);
+                throw new OnErrorNotImplementedException(e);
+            }
+
+            @Override
+            public void onNext(T args) {
+                // do nothing
+            }
+
+        });
+    }
+    
     /**
      * An {@link Observer} must call an Observable's {@code subscribe} method
      * in order to receive items and notifications from the Observable.