public boolean containsRegionRef(Id regionId) {
		if (members != null) {
			for (Iterator<GroupMember> it = members.iterator(); it.hasNext(); ) {
				GroupMember member = it.next();
				if (member instanceof RegionRef) {
					if (((RegionRef)member).getRegionId().equals(regionId))
						return true;
				} else { //if (member instanceof Group) 
					if (((Group)member).containsRegionRef(regionId)) //Recursion
						return true;
				}
			}
		}
		return false;
	}