code: public Observable<VirtualMachineExtensionImageInner> getAsync(String location, String publisherName, String type, String version) {
          return getWithServiceResponseAsync(location, publisherName, type, version).map(new Func1<ServiceResponse<VirtualMachineExtensionImageInner>, VirtualMachineExtensionImageInner>() {
              @Override
              public VirtualMachineExtensionImageInner call(ServiceResponse<VirtualMachineExtensionImageInner> response) {
                  return response.body();
              }
          });
      }
docs: Gets a virtual machine extension image.
  
  @param location The name of a supported Azure region.
  @param publisherName the String value
  @param type the String value
  @param version the String value
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the VirtualMachineExtensionImageInner object