code: public Observable<SkuInfosInner> listSkusAsync() {
          return listSkusWithServiceResponseAsync().map(new Func1<ServiceResponse<SkuInfosInner>, SkuInfosInner>() {
              @Override
              public SkuInfosInner call(ServiceResponse<SkuInfosInner> response) {
                  return response.body();
              }
          });
      }
docs: List all SKUs.
  List all SKUs.
  
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the SkuInfosInner object