multiTrackParameters set used in GSF or other Fitters

The Gsf need a MultiTrackParameter class to deal with the parameters of different components, like to calculate distance, to merge component using the parameter information of each component

alike with the SingleTrackParameter , The structure would be

Now the idea is in the MultiTrackParameter, it contains a map like < pair<weight,TrackParamterBase*>, id , std::greater > , the pair can sort with the weight of component , id is to reserve the serial number in the multi-component list so that can kill the component with id.

Let's discuss if there is some better solutions of the inner data structure