public function testGetAppenderExists()
 {
     $hierarchy = new LoggerHierarchy();
     $appender = new AppenderStd();
     $hierarchy->setAppender('appender', $appender);
     $this->assertSame($appender, $hierarchy->getAppender('appender'));
     $this->assertSame(['appender' => $appender], $hierarchy->getAppenderMap());
 }