     
     //MARK: - Node
     
-    public func register(_ aNode: Node) {
+    var nodeList = [Node]()
+    var maxNodeUID : UID = 0
+    
+    public func register(_ node: Node) {
+        maxNodeUID += 1
+        node.uid = maxNodeUID
+        nodeList.append(node)
     }
     
     public func update(_ aNode: Node) {
-        // TODO
+        // No implementation required for XMLFileStore
     }
     
     public func delete(_ aNode: Node) {
-        // TODO
+        // No implementation required for XMLFileStore
     }
     
     //MARK: - Relationship
     
+    //var relationshipList = [Relationship]()
+    var maxRelationshipUID : UID = 0
+    
     public func register(_ aRelationship: Relationship) {
-        // TODO
+        maxRelationshipUID += 1
+        aRelationship.uid = maxRelationshipUID
     }
     
     public func delete(_ aRelationship: Relationship) {
         // TODO
+    }
+    
+
+
+    
+    public func update(_ relationship: Relationship) {
+        // No implementation required for XMLFileStore
     }
     
     public func findRelationship(from startNode: Node, to endNode: Node) -> Relationship?{

        return nil
    }
    

    
    public func update(_ aRelationship: Relationship) {
        // TODO
    }
    

    public func readXMLFile() throws {
        
        //var error : NSError?
        

public class XMLFileStore : SOGraphDBStore {

    open let xmlFileURL : URL
    
    //MARK:  -
    
