code: def _update_solution_data(self, s, HH, CC, C0):
          
          x = s["x"]
          Va_v = self.om.get_var("Va")
          Pg_v = self.om.get_var("Pg")
  
          Va = x[Va_v.i1:Va_v.iN + 1]
          Pg = x[Pg_v.i1:Pg_v.iN + 1]
  #        f = 0.5 * dot(x.T * HH, x) + dot(CC.T, x)
  
          s["f"] = s["f"] + C0
  
          # Put the objective function value in the solution.
  #        solution["f"] = f
  
          return Va, Pg
docs: Returns the voltage angle and generator set-point vectors.