@Nullable
  @Override
  protected JvmElementVisitor<Boolean> buildVisitor(@NotNull Project project, @NotNull HighlightSink sink, boolean isOnTheFly) {
    return new DefaultJvmElementVisitor<>() {
      @Override
      public Boolean visitClass(@NotNull JvmClass clazz) {
        PsiElement sourceElement = clazz.getSourceElement();
        if (!(sourceElement instanceof PsiClass)) {
          return null;
        }
        checkClass(project, (PsiClass)sourceElement, sink);
        return false;
      }
    };
  }
@Nullable
  @Override
  protected JvmElementVisitor<Boolean> buildVisitor(@NotNull Project project, @NotNull HighlightSink sink, boolean isOnTheFly)