static private bool IsElementBelongsToCircuit(MEPModel mepModel,
                                                      ElectricalSystem selectedElectricalSystem)
        {
            ISet <ElectricalSystem> ess = mepModel.GetElectricalSystems();

            if (null == ess || !ess.Contains(selectedElectricalSystem))
            {
                return(false);
            }

            return(true);
        }