add Requirement fo Refactoring XReference Mechanism ...

Models/XReference.cs

@@ -0,0 +1,9 @@
+namespace xDataService.Models
+{
+    public class XReference<T>
+    {
+        public int Index { get; set; }
+        public T ReferencedTo { get; set; }
+        public string ProvidedFor { get; set; }
+    }
+}