private static boolean isNewStringConcatenatorChain(PsiExpression expression) {
      while (true) {
        if (expression == null) return false;
        if (expression instanceof PsiNewExpression) {
          return isConcatenatorConstruction((PsiNewExpression)expression);
        }
        if (!(expression instanceof PsiMethodCallExpression call)) return false;
        if (!isAppendCall(call)) return false;
        expression = PsiUtil.skipParenthesizedExprDown(call.getMethodExpression().getQualifierExpression());
      }
    }
private static boolean isNewStringConcatenatorChain(PsiExpression expression)