I am trying access the value of a content item before the item is saved. I am using ContentSavingNotification however IContent contains the previous state before any changes have been made so I cannot detect a change that shouldn't happen and then cancel the saving event.

This is what I have in V9

public void Handle(ContentSavingNotification notification)
{
       foreach (var content in notification.SavedEntities)
       {
            //content is giving me the previous values before any changes.
       }
}

Does anyone know how I can access the values that are about to be saved so that I can determine if I want to allow the save event to complete or not?