if (parent == null) { return null; } HashMap pslots = (HashMap) proto_slots.get(parent); if (pslots != null && pslots.containsKey(slot)) { return parent; }
    private String ancestorForSlot(String proto, String slot)    {	Attributes attrs = (Attributes) proto_attrs.get(proto);	String parent = attrs.getValue("prototype");	if (parent == null) {	    return null;	}	HashMap pslots = (HashMap) proto_slots.get(parent);	if (pslots != null && pslots.containsKey(slot)) {	    return parent;	}	return ancestorForSlot(parent, slot);    }