code: def _update_summary(self, system):
          
          self.basic.update({
              'nbus': system.Bus.n,
              'ngen': system.PV.n + system.SW.n,
              'ngen_on': sum(system.PV.u) + sum(system.SW.u),
              'nload': system.PQ.n,
              'nshunt': system.Shunt.n,
              'nline': system.Line.n,
              'ntransf': system.Line.trasf.count(True),
              'narea': system.Area.n,
          })
docs: Update the summary data
  
          Parameters
          ----------
          system
  
          Returns
          -------
          None