code: public Observable<List<VirtualMachineImageResourceInner>> listOffersAsync(String location, String publisherName) {
          return listOffersWithServiceResponseAsync(location, publisherName).map(new Func1<ServiceResponse<List<VirtualMachineImageResourceInner>>, List<VirtualMachineImageResourceInner>>() {
              @Override
              public List<VirtualMachineImageResourceInner> call(ServiceResponse<List<VirtualMachineImageResourceInner>> response) {
                  return response.body();
              }
          });
      }
docs: Gets a list of virtual machine image offers for the specified location and publisher.
  
  @param location The name of a supported Azure region.
  @param publisherName A valid image publisher.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the List&lt;VirtualMachineImageResourceInner&gt; object