@Override
	public void checkInstantiationRestriction(ModelInstance m)
			throws RestrictionException {
		Iterator<Map.Entry<Integer, ClassInstance>> it = m.instanced_classes.entrySet().iterator();
		
		while(it.hasNext()) {
			ClassInstance c = it.next().getValue();
			if(c.meta.name.equals("Feature") || c.meta.name.equals("Concept")) {
				for(int i = 0; i < c.attributes.size(); ++i) {
					if(c.attributes.get(i).meta.name.equals("open") && 
							(!c.attributes.get(i).value.equalsIgnoreCase("True") && !c.attributes.get(i).value.equalsIgnoreCase("False")))
						throw new RestrictionException("Feature " + c.instance_name + " must have open true or false!");
				}
			}
		}
	}