Bug 172765 [DataBinding] Consistency when registering property change listeners
bundles/org.eclipse.core.databinding.beans/src/org/eclipse/core/databinding/beans/BeansObservables.java
}
	/**
	 * @param realm
	 * @param bean
	 * @param propertyName
	 * @param elementType
	 *            can be <code>null</code>
	 * @return an observable set that tracks the current value of the named
	 *         property for given bean object
	 */
	public static IObservableSet observeSet(Realm realm, Object bean,
			String propertyName, Class elementType) {
		PropertyDescriptor propertyDescriptor = getPropertyDescriptor(bean
				.getClass(), propertyName);
		elementType = getCollectionElementType(elementType, propertyDescriptor);
		return new JavaBeanObservableSet(realm, bean, propertyDescriptor,
				elementType);
	}
	/**
	 * @param realm
	 * @param propertyName
	 * @param elementType
	 *            can be <code>null</code>
	 * @return an observable set factory for creating observable sets
	 */
	public static IObservableFactory setFactory(final Realm realm,
			final String propertyName, final Class elementType) {
		return new IObservableFactory() {
			public IObservable createObservable(Object target) {
				return observeSet(realm, target, propertyName, elementType);