internal override DispatchCommand GetLastExecutedCommand(DispatchCommand last) {
     if (last.Is<ConfirmTrackStretchCommand>()) {
         Call.IsDeparted = true;
         return this;
     }
     return last;
 }
 internal override DispatchCommand GetLastExecutedCommand(DispatchCommand last) {
     if (last.Is<DepartureTrackStretchCommand>()) {
         Call.IsArrived = true;
         return NullCommand;
     }
     return last;
 }
 internal override DispatchCommand GetLastExecutedCommand(DispatchCommand last) {
     if (last.Is< RequestTrackStretchCommand>() || last.Is< ConfirmTrackStretchCommand>()) return NullCommand;
     return last;
 }
 internal override DispatchCommand GetLastExecutedCommand(DispatchCommand last) {
     if (last.Is<RequestTrackStretchCommand>()) return this;
     return last;
 }