code: public Observable<Page<ServerInner>> listAsync() {
          return listWithServiceResponseAsync().map(new Func1<ServiceResponse<List<ServerInner>>, Page<ServerInner>>() {
              @Override
              public Page<ServerInner> call(ServiceResponse<List<ServerInner>> response) {
                  PageImpl<ServerInner> page = new PageImpl<>();
                  page.setItems(response.body());
                  return page;
              }
          });
      }
docs: List all the servers in a given subscription.
  
  @return the observable to the List&lt;ServerInner&gt; object