code: public Observable<ServiceResponse<NameAvailabilityResponseInner>> checkChildrenNameAvailabilityWithServiceResponseAsync(String groupName, String serviceName, NameAvailabilityRequest parameters) {
          if (this.client.subscriptionId() == null) {
              throw new IllegalArgumentException("Parameter this.client.subscriptionId() is required and cannot be null.");
          }
          if (groupName == null) {
              throw new IllegalArgumentException("Parameter groupName is required and cannot be null.");
          }
          if (serviceName == null) {
              throw new IllegalArgumentException("Parameter serviceName is required and cannot be null.");
          }
          if (this.client.apiVersion() == null) {
              throw new IllegalArgumentException("Parameter this.client.apiVersion() is required and cannot be null.");
          }
          if (parameters == null) {
              throw new IllegalArgumentException("Parameter parameters is required and cannot be null.");
          }
          Validator.validate(parameters);
          return service.checkChildrenNameAvailability(this.client.subscriptionId(), groupName, serviceName, this.client.apiVersion(), parameters, this.client.acceptLanguage(), this.client.userAgent())
              .flatMap(new Func1<Response<ResponseBody>, Observable<ServiceResponse<NameAvailabilityResponseInner>>>() {
                  @Override
                  public Observable<ServiceResponse<NameAvailabilityResponseInner>> call(Response<ResponseBody> response) {
                      try {
                          ServiceResponse<NameAvailabilityResponseInner> clientResponse = checkChildrenNameAvailabilityDelegate(response);
                          return Observable.just(clientResponse);
                      } catch (Throwable t) {
                          return Observable.error(t);
                      }
                  }
              });
      }
docs: Check nested resource name validity and availability.
  This method checks whether a proposed nested resource name is valid and available.
  
  @param groupName Name of the resource group
  @param serviceName Name of the service
  @param parameters Requested name to validate
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the NameAvailabilityResponseInner object