# System.Data

``` diff
 namespace System.Data {
     public sealed class DBConcurrencyException : SystemException {
-        public override void GetObjectData(SerializationInfo si, StreamingContext context);
+        public override void GetObjectData(SerializationInfo info, StreamingContext context);
     }
-    public class PropertyCollection : Hashtable
+    public class PropertyCollection : Hashtable, ICloneable
 }
```