private function debugLog($message)
    {
        $this->debug_log_handler !== null && is_callable($this->debug_log_handler) && call_user_func($this->debug_log_handler, $message);
    }
private function debugLog($message)
    {
        $this->debug_log_handler !== null && is_callable($this->debug_log_handler) && call_user_func($this->debug_log_handler, $message);
    }
private function debugLog ( $ message ) { $ this -> debug_log_handler !== null && is_callable ( $ this -> debug_log_handler ) && call_user_func ( $ this -> debug_log_handler , $ message ) ; }
Write to debug log

@param $message
Write to debug log