diff --git a/ln.types.csproj b/ln.types.csproj
index df7b82a..e7d1584 100644
--- a/ln.types.csproj
+++ b/ln.types.csproj
@@ -116,6 +116,9 @@
     <Compile Include="test\CacheTests.cs" />
     <Compile Include="test\ODBTests.cs" />
     <Compile Include="test\TypesTests.cs" />
+    <Compile Include="odb\ng\diff\Diff.cs" />
+    <Compile Include="odb\ng\diff\DocumentDiff.cs" />
+    <Compile Include="odb\ng\diff\ListDiff.cs" />
   </ItemGroup>
   <ItemGroup>
     <Folder Include="odb\" />
diff --git a/odb/ng/diff/Diff.cs b/odb/ng/diff/Diff.cs
index 08a43c5..b784f69 100644
--- a/odb/ng/diff/Diff.cs
+++ b/odb/ng/diff/Diff.cs
@@ -5,9 +5,9 @@ namespace ln.types.odb.ng.diff
     public abstract class Diff
     {
 
-        public abstract ODBValue Apply(ODBValue src);
+        public abstract ODBEntity Apply(ODBEntity src);
 
-        public static Diff Construct(ODBValue src,ODBValue dst)
+        public static Diff Construct(ODBEntity src,ODBEntity dst)
         {
             if (!src.GetType().Equals(dst.GetType()))
             {
@@ -27,14 +27,14 @@ namespace ln.types.odb.ng.diff
 
         class SimpleDiff : Diff
         {
-            public ODBValue DestinationValue { get; }
+            public ODBEntity DestinationValue { get; }
 
-            public SimpleDiff(ODBValue dst)
+            public SimpleDiff(ODBEntity dst)
             {
-                DestinationValue = dst.Clone();
+                DestinationValue = dst;
             }
 
-            public override ODBValue Apply(ODBValue src)
+            public override ODBEntity Apply(ODBEntity src)
             {
                 return DestinationValue;
             }
diff --git a/odb/ng/diff/DocumentDiff.cs b/odb/ng/diff/DocumentDiff.cs
index 8d4f279..d2c1287 100644
--- a/odb/ng/diff/DocumentDiff.cs
+++ b/odb/ng/diff/DocumentDiff.cs
@@ -6,22 +6,22 @@ namespace ln.types.odb.ng.diff
 {
     public class DocumentDiff : Diff
     {
-        Dictionary<ODBValue, Diff> propertyDiffs = new Dictionary<ODBValue, Diff>();
+        Dictionary<ODBEntity, Diff> propertyDiffs = new Dictionary<ODBEntity, Diff>();
 
         public DocumentDiff(Document src, Document dst)
         {
-            HashSet<ODBValue> keys = new HashSet<ODBValue>(src.Keys);
-            foreach (ODBValue key in dst.Keys)
+            HashSet<ODBEntity> keys = new HashSet<ODBEntity>(src.Keys);
+            foreach (ODBEntity key in dst.Keys)
                 keys.Add(key);
 
-            foreach (ODBValue key in keys)
+            foreach (ODBEntity key in keys)
             {
                 if (!src[key].Equals(dst[key]))
                     propertyDiffs.Add(key, Diff.Construct(src[key], dst[key]));
             }
         }
 
-        public override ODBValue Apply(ODBValue src)
+        public override ODBEntity Apply(ODBEntity src)
         {
             Document srcDocument = src as Document;
 
diff --git a/odb/ng/diff/ListDiff.cs b/odb/ng/diff/ListDiff.cs
index 2b81f64..d0fe63f 100644
--- a/odb/ng/diff/ListDiff.cs
+++ b/odb/ng/diff/ListDiff.cs
@@ -11,7 +11,7 @@ namespace ln.types.odb.ng.diff
 
         }
 
-        public override ODBValue Apply(ODBValue src)
+        public override ODBEntity Apply(ODBEntity src)
         {
             throw new NotImplementedException();
         }
diff --git a/odb/ng/storage/session/SessionStorage.cs b/odb/ng/storage/session/SessionStorage.cs
index 2ff37a3..22f9667 100644
--- a/odb/ng/storage/session/SessionStorage.cs
+++ b/odb/ng/storage/session/SessionStorage.cs
@@ -4,6 +4,7 @@ using ln.types.odb.values;
 using System.Linq;
 using ln.types.odb.ng.storage.bases;
 using ln.types.threads;
+using ln.types.odb.ng.diff;
 namespace ln.types.odb.ng.storage.session
 {
 	class SessionStorage : ChainedStorage
@@ -118,14 +119,12 @@ namespace ln.types.odb.ng.storage.session
                 if (!GetStorageTimestamp(document.ID).Equals(document.StorageTimeStamp))
                 {
                     Document cacheDocument = cachedDocument.CachedCopy;
-
                     Document storageDocument = Storage.Load(document.ID);
 
-                    DocumentChanges storageChanges = new DocumentChanges(cacheDocument, storageDocument);
-                    DocumentChanges sessionChanges = new DocumentChanges(cacheDocument, document);
-
-                    Document prepare = cacheDocument.Clone() as Document;
+                    DocumentDiff cacheDiff = new DocumentDiff(cacheDocument, document);
+                    DocumentDiff storageDiff = new DocumentDiff(cacheDocument, storageDocument);
 
+                     
 
 
                 }