Since VCase cannot handle actions properly, the model below causes a crash.

case c1 {
        first start;
        then action a;
}

This PR fixes this issue and lets the visualizer properly render actions as well as cases.

This fixes the crash, so the example case renders as

If the example is changed to an analysis case or a verification case, it renders similarly. However, a use case renders as

without the start symbol. Why is that?

Opps, it is because UseCases::UseCase::start redefines Actions::Action::start and the current code uses:
return "Actions::Action::start".equals(f.getQualifiedName());

Is there any good utility function to check if the element belongs to start or done? If not, I will simply compare the qualified name with UseCases::UseCase::start as well.

Opps, it is because UseCases::UseCase::start redefines Actions::Action::start and the current code uses: return "Actions::Action::start".equals(f.getQualifiedName());

Is there any good utility function to check if the element belongs to start or done? If not, I will simply compare the qualified name with UseCases::UseCase::start as well.

If f is a Type, then you can check f.specializesFromLibrary("Actions::Action::start").