code: public static ServiceFuture<Void> fromBody(final Completable completable, final ServiceCallback<Void> callback) {
          final ServiceFuture<Void> serviceFuture = new ServiceFuture<>();
          completable.subscribe(new Action0() {
              Void value = null;
              @Override
              public void call() {
                  if (callback != null) {
                      callback.success(value);
                  }
                  serviceFuture.set(value);
              }
          }, new Action1<Throwable>() {
              @Override
              public void call(Throwable throwable) {
                  if (callback != null) {
                      callback.failure(throwable);
                  }
                  serviceFuture.setException(throwable);
              }
          });
          return serviceFuture;
      }
docs: Creates a ServiceFuture from an Completable object and a callback.
  
  @param completable the completable to create from
  @param callback the callback to call when event happen
  @return the created ServiceFuture