public void SetNotDirtyState ()
{
OptimizeTypedUndo ();
if (undoStack.Count > 0 && undoStack.Peek () is KeyboardStackUndo)
((KeyboardStackUndo)undoStack.Peek ()).IsClosed = true;
savePoint = undoStack.ToArray ();
this.CommitUpdateAll ();
DiffTracker.SetBaseDocument (CreateDocumentSnapshot ());
}