This method is invoked right after relabelling finishes.
This method is invoked right after relabelling finishes. That is, the items in
the clean
iterator have been relabelled and the tags carry their new values.
This method is invoked right before relabelling starts.
This method is invoked right before relabelling starts. That is, the items in
the dirty
iterator are about to be relabelled, but at the point of calling
this method the tags still carry their previous values.