boolean addObserver(ApptentiveNotificationObserver observer, boolean useWeakReference) {
		if (observer == null) {
			throw new IllegalArgumentException("Observer is null");
		}

		if (!contains(observer)) {
			observers.add(useWeakReference ? new ObserverWeakReference(observer) : observer);
			return true;
		}

		return false;
	}
boolean addObserver ( ApptentiveNotificationObserver observer , boolean useWeakReference ) { if ( observer == null ) { throw new IllegalArgumentException ( "Observer is null" ) ; } if ( ! contains ( observer ) ) { observers . add ( useWeakReference ? new ObserverWeakReference ( observer ) : observer ) ; return true ; } return false ; }
Adds an observer to the list without duplicates.

@param useWeakReference - use weak reference if <code>true</code>
@return <code>true</code> - if observer was added