code: public Observable<ServiceResponse<ConnectivityInformationInner>> checkConnectivityWithServiceResponseAsync(String resourceGroupName, String networkWatcherName, ConnectivityParameters parameters) {
          if (resourceGroupName == null) {
              throw new IllegalArgumentException("Parameter resourceGroupName is required and cannot be null.");
          }
          if (networkWatcherName == null) {
              throw new IllegalArgumentException("Parameter networkWatcherName 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 (parameters == null) {
              throw new IllegalArgumentException("Parameter parameters is required and cannot be null.");
          }
          Validator.validate(parameters);
          final String apiVersion = "2018-06-01";
          Observable<Response<ResponseBody>> observable = service.checkConnectivity(resourceGroupName, networkWatcherName, this.client.subscriptionId(), parameters, apiVersion, this.client.acceptLanguage(), this.client.userAgent());
          return client.getAzureClient().getPostOrDeleteResultAsync(observable, new TypeToken<ConnectivityInformationInner>() { }.getType());
      }
docs: Verifies the possibility of establishing a direct TCP connection from a virtual machine to a given endpoint including another VM or an arbitrary remote server.
  
  @param resourceGroupName The name of the network watcher resource group.
  @param networkWatcherName The name of the network watcher resource.
  @param parameters Parameters that determine how the connectivity check will be performed.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable for the request