@Contract("null -> false")
  private static boolean isSimpleReference(PsiExpression expression) {
    if (!(expression instanceof PsiReferenceExpression ref)) return false;
    PsiExpression qualifier = ref.getQualifierExpression();
    if (qualifier != null) {
      if (!(qualifier instanceof PsiQualifiedExpression) || ((PsiQualifiedExpression)qualifier).getQualifier() != null) return false; 
    }
    return ref.resolve() instanceof PsiVariable;
  }
@Contract("null -> false")
  private static boolean isSimpleReference(PsiExpression expression)