package Ġcom . re vol gen x . an ilib . user . data . model . stats Ċ Ċ import Ġcom . re vol gen x . an ilib . staff . data . model . Staff Model ĊĊ Ċ class ĠUser Staff Statistic Model Ġ: ĠBase Statistic Model () Ġ{ ĊĠĠĠ Ġvar Ġstaff : Staff Model ? Ġ= Ġnull Ċ }