LoggerChannel example

  protected $loggers = [];

  /** * {@inheritdoc} */
  public function get($channel) {
    if (!isset($this->channels[$channel])) {
      $instance = new LoggerChannel($channel);

      // If we have a container set the request_stack and current_user services       // on the channel. It is up to the channel to determine if there is a       // current request.       if ($this->container) {
        $instance->setRequestStack($this->container->get('request_stack'));
        $instance->setCurrentUser($this->container->get('current_user'));
      }

      // Pass the loggers to the channel.       $instance->setLoggers($this->loggers);
      

  public function testLog(callable $expected, Request $request = NULL, AccountInterface $current_user = NULL) {
    $channel = new LoggerChannel('test');
    $message = $this->randomMachineName();
    $logger = $this->createMock('Psr\Log\LoggerInterface');
    $logger->expects($this->once())
      ->method('log')
      ->with($this->anything(), $message, $this->callback($expected));
    $channel->addLogger($logger);
    if ($request) {
      $requestStack = new RequestStack();
      $requestStack->push($request);
      $channel->setRequestStack($requestStack);
    }