Handle(AIS_InteractiveContext) aContext = myWorkshop->viewer()->AISContext();
if (!aContext.IsNull()) {
/// previous selection should be cleared, else there will be decomposition of selections:
Handle(AIS_InteractiveContext) aContext = myWorkshop->viewer()->AISContext();
if (!aContext.IsNull()) {
/// previous selection should be cleared, else there will be decomposition of selections: