code: public Observable<ServiceResponse<List<VirtualMachineExtensionImageInner>>> listTypesWithServiceResponseAsync(String location, String publisherName) {
          if (location == null) {
              throw new IllegalArgumentException("Parameter location is required and cannot be null.");
          }
          if (publisherName == null) {
              throw new IllegalArgumentException("Parameter publisherName is required and cannot be null.");
          }
          if (this.client.subscriptionId() == null) {
              throw new IllegalArgumentException("Parameter this.client.subscriptionId() is required and cannot be null.");
          }
          if (this.client.apiVersion() == null) {
              throw new IllegalArgumentException("Parameter this.client.apiVersion() is required and cannot be null.");
          }
          return service.listTypes(location, publisherName, this.client.subscriptionId(), this.client.apiVersion(), this.client.acceptLanguage(), this.client.userAgent())
              .flatMap(new Func1<Response<ResponseBody>, Observable<ServiceResponse<List<VirtualMachineExtensionImageInner>>>>() {
                  @Override
                  public Observable<ServiceResponse<List<VirtualMachineExtensionImageInner>>> call(Response<ResponseBody> response) {
                      try {
                          ServiceResponse<List<VirtualMachineExtensionImageInner>> clientResponse = listTypesDelegate(response);
                          return Observable.just(clientResponse);
                      } catch (Throwable t) {
                          return Observable.error(t);
                      }
                  }
              });
      }
docs: Gets a list of virtual machine extension image types.
  
  @param location The name of a supported Azure region.
  @param publisherName the String value
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the List&lt;VirtualMachineExtensionImageInner&gt; object