code: public Observable<ServiceResponse<ContainerExecResponseInner>> executeCommandWithServiceResponseAsync(String resourceGroupName, String containerGroupName, String containerName, ContainerExecRequest containerExecRequest) {
          if (this.client.subscriptionId() == null) {
              throw new IllegalArgumentException("Parameter this.client.subscriptionId() is required and cannot be null.");
          }
          if (resourceGroupName == null) {
              throw new IllegalArgumentException("Parameter resourceGroupName is required and cannot be null.");
          }
          if (containerGroupName == null) {
              throw new IllegalArgumentException("Parameter containerGroupName is required and cannot be null.");
          }
          if (containerName == null) {
              throw new IllegalArgumentException("Parameter containerName 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 (containerExecRequest == null) {
              throw new IllegalArgumentException("Parameter containerExecRequest is required and cannot be null.");
          }
          Validator.validate(containerExecRequest);
          return service.executeCommand(this.client.subscriptionId(), resourceGroupName, containerGroupName, containerName, this.client.apiVersion(), containerExecRequest, this.client.acceptLanguage(), this.client.userAgent())
              .flatMap(new Func1<Response<ResponseBody>, Observable<ServiceResponse<ContainerExecResponseInner>>>() {
                  @Override
                  public Observable<ServiceResponse<ContainerExecResponseInner>> call(Response<ResponseBody> response) {
                      try {
                          ServiceResponse<ContainerExecResponseInner> clientResponse = executeCommandDelegate(response);
                          return Observable.just(clientResponse);
                      } catch (Throwable t) {
                          return Observable.error(t);
                      }
                  }
              });
      }
docs: Executes a command in a specific container instance.
  Executes a command for a specific container instance in a specified resource group and container group.
  
  @param resourceGroupName The name of the resource group.
  @param containerGroupName The name of the container group.
  @param containerName The name of the container instance.
  @param containerExecRequest The request for the exec command.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the ContainerExecResponseInner object