private function logStatusChange( $status, $reason = null )
    {
        $contentObjectId = $this->version()->attribute( 'contentobject_id' );
        $versionNumber = $this->version()->attribute( 'version' );
        eZDebugSetting::writeDebug(
            'kernel-content-publish',
            sprintf(
                "process #%d, content %d.%d, status changed to %s (reason: %s)",
                $this->attribute( 'ezcontentobject_version_id' ),
                $contentObjectId,
                $versionNumber,
                $this->getStatusString( $status ),
                $reason ?: "none given"
            ),
            'Asynchronous publishing process status changed'
        );
    }