private bool _ContainsEntity(EntityObject entity)
        {
            Debug.Assert(entity != null);

            IEnumerable <ObjectStateEntry> entries = ObjectContext.ObjectStateManager.GetObjectStateEntries(
                EntityState.Added);

            bool res = false;

            foreach (ObjectStateEntry entry in entries)
            {
                EntityObject addedEntity = (EntityObject)entry.Entity;
                if (addedEntity != null && addedEntity.Equals(entity))
                {
                    res = true;
                    break;
                }
            }

            return(res);
        }