code: public Observable<List<LocationInner>> listLocationsAsync(String subscriptionId) {
          return listLocationsWithServiceResponseAsync(subscriptionId).map(new Func1<ServiceResponse<List<LocationInner>>, List<LocationInner>>() {
              @Override
              public List<LocationInner> call(ServiceResponse<List<LocationInner>> response) {
                  return response.body();
              }
          });
      }
docs: Gets all available geo-locations.
  This operation provides all the locations that are available for resource providers; however, each resource provider may support a subset of this list.
  
  @param subscriptionId The ID of the target subscription.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the List&lt;LocationInner&gt; object