/**
* Initializes this instance and starts background tasks required by <tt>RESTReservations</tt> to
* work properly.
*
* @param focusManager <tt>FocusManager</tt> instance that manages conference pool.
*/
public void start(FocusManager focusManager) {
if (this.focusManager != null) throw new IllegalStateException("already started");
if (focusManager == null) throw new NullPointerException("focusManager");
this.focusManager = focusManager;
focusManager.setFocusAllocationListener(this);
confDurationGuard = new Timer("ConferenceDuartionGuard");
confDurationGuard.scheduleAtFixedRate(
new ConferenceExpireTask(), EXPIRE_INTERVAL, EXPIRE_INTERVAL);
}
