         //readXMLFile()
     }
     
+    //MARK: - Graphs
+    
+    var graphList = [Graph]()
+    
+    public func register(_ graph: Graph) {
+        graphList.append(graph)
+    }
+
     //MARK: - Node
     
     //var nodeList = [Node]()

        return nil
    }
    
    
    public func update(_ aNode: Node) {
        // No implementation required for XMLFileStore

        // No implementation required for XMLFileStore
    }
    
    //MARK: - Relationship
    
    var relationshipList = [Relationship]()
    var maxRelationshipUID : UID = 0
    
    func onAllRelationships(_ closure: (Relationship) -> Void) {
        for rel in relationshipList {
            closure(rel)
        }
    }
    
    // Register a new or loaded relationship
    public func register(_ rel: Relationship) {
