need more detail document for QContactRingtone Class

Suggestion:
For function: void QContactRingtone::setVibrationRingtoneUrl ( const QUrl & vibrationRingtoneUrl )
QUrl QContactRingtone::vibrationRingtoneUrl () const
Description is too simple, it's better to give out a example code or demo.
And its better to give out the resource of vibration file which canbe play through corresponding url.
Reason:
Developer don't know how to use these interface. Are these interfaces just supported by "Contact" app? Other app can use them too?