/**
  * Sets logging callback to use
  * @param string $loggingCallback Logging callback
  */
 public static function setLoggingCallback($loggingCallback)
 {
     self::$loggingCallback = $loggingCallback;
 }
 public function testLoggingCallback()
 {
     $callback = SSGoogleAnalytics::getLoggingCallback();
     $this->assertEquals(get_class($callback), 'Closure');
     $this->assertEquals($callback('testLoggingCallback'), 'testLoggingCallback');
 }