The primary output of the RICH digitisation simulation, as provided by the package Rich/RichReadout.
Each MCRichDigit is stored in its container with a key that is a RichSmartID, a bit-packed integer that encodes a particular RICH readout channel.
The additional data members are :-
A bit pack history code integer. Currently only contains the event the hit came from (signal or spillover).
A container of smart references to the MCRichHits that fell into the channel associated to this digit