public @Nullable PsiClass findUsageClass(PsiMember member) {
      ProgressManager.getInstance().runProcess(() -> {
        final Query<PsiReference> query = member instanceof PsiMethod method
                                          ? MethodReferencesSearch.search(method)
                                          : ReferencesSearch.search(member);
        if (!query.forEach(this)) {
          foundClass.set(null);
        }
      }, null);
      return foundClass.get();
    }
public @Nullable PsiClass findUsageClass(PsiMember member)