code: public Observable<EventInfoInner> pingAsync(String resourceGroupName, String registryName, String webhookName) {
          return pingWithServiceResponseAsync(resourceGroupName, registryName, webhookName).map(new Func1<ServiceResponse<EventInfoInner>, EventInfoInner>() {
              @Override
              public EventInfoInner call(ServiceResponse<EventInfoInner> response) {
                  return response.body();
              }
          });
      }
docs: Triggers a ping event to be sent to the webhook.
  
  @param resourceGroupName The name of the resource group to which the container registry belongs.
  @param registryName The name of the container registry.
  @param webhookName The name of the webhook.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the EventInfoInner object