this.domain = domain;
    public SingleInheritanceFrameSet(String pkg,				     ServiceBroker sb,				     BlackboardService bbs,				     String name,				     String container_relation,				     String primaryIndexSlot) {	this.name = name;	this.primaryIndexSlot = primaryIndexSlot;	this.container_relation = container_relation;	this.cached_classes = new HashMap<String,Class>();	this.parent_cache = new HashMap<RelationFrame,DataFrame>();	this.child_cache = new HashMap<RelationFrame,DataFrame>();	this.inverse_child_cache = new HashMap<DataFrame,Set<RelationFrame>>();	this.inverse_parent_cache = new HashMap<DataFrame,Set<RelationFrame>>();	this.paths = new HashMap<String,Path>();	this.frames = new HashSet<DataFrame>();	this.primaryIndexCache = new HashMap<PrototypeFrame,Map<Object, DataFrame>>();	this.pkg = pkg;	this.bbs = bbs;	this.change_queue = new ArrayList();	this.change_queue_lock = new Object();	this.relation_lock = new Object();	log = (LoggingService)	    sb.getService(this, LoggingService.class, null);	uids = (UIDService)	    sb.getService(this, UIDService.class, null);	metrics = (MetricsService)	    sb.getService(this, MetricsService.class, null); 	this.kb = new HashMap<UID,Object>();	this.prototypes = new HashMap<String,PrototypeFrame>();	this.pending_relations = new HashSet<RelationFrame>();	this.containers = new HashMap<DataFrame,DataFrame>();	this.aggregations = new HashSet<SlotAggregation>();    }