public String toString() { return title + "@" + hashCode() + " [" + ((tail != null) ? tail.getTitle() + "@" + tail.hashCode() : "NULL") + ((directed) ? LEdge.DIRECTED_STR : LEdge.UNDIRECTED_STR) + ((head != null) ? head.getTitle() + "@" + head.hashCode() : "NULL") + "]"; }