@Override
  public void visitReferenceExpression(
    @NotNull PsiReferenceExpression referenceExpression) {
    if (used) {
      return;
    }
    super.visitReferenceExpression(referenceExpression);
    if (referenceExpression.isReferenceTo(variable)) {
      used = true;
    }
  }
@Override
  public void visitReferenceExpression(
    @NotNull PsiReferenceExpression referenceExpression)