@Override
  public void visitReferenceExpression(@NotNull PsiReferenceExpression ref) {
    super.visitReferenceExpression(ref);
    PsiElement element = ref.resolve();

    if (element instanceof PsiModifierListOwner owner &&
        !owner.hasModifierProperty(PsiModifier.STATIC) &&
        !(owner instanceof PsiClass cls && ClassUtil.isTopLevelClass(cls))) {
      canBeStatic = false;
      stopWalking();
    }
  }
@Override
  public void visitReferenceExpression(@NotNull PsiReferenceExpression ref)