我目前正在编写一个Node.js脚本，其中涉及使用xml2js库解析XML文件。该脚本读取XML文件，提取特定元素，并使用xml2js.Builder（）构建新的XML输出。
对于简单的XML结构，该脚本工作得非常好。但是，当我遇到包含嵌套元素（<customs>元素）的XML文件时，它会抛出Invalid character in name错误。

const fs = require('fs');
const xml2js = require('xml2js');
const XmlStream = require('xml-stream');

const stream = fs.createReadStream('./test.xml');
const xmlStream = new XmlStream(stream);
const builder = new xml2js.Builder();

const MAX_ITEMS = 1;
let lists = [];
let listCount = 0;

xmlStream.on('endElement: list', function (item) {
  if (listCount < MAX_ITEMS) {
    lists.push(item);
    listCount++;
  } else {
    stream.destroy();
  }
});

stream.on('close', function () { 
   const outputXml = builder.buildObject({ lists: { list: lists } });
   console.log(outputXml);
});

XML文件：

<?xml version="1.0" encoding="UTF-8"?>
<lists>
  <list list-id="0001">
    <first-name>first-name-1</first-name>
    <last-name>second-name-1</last-name>
    <customs>
      <custom attribute-id="gender">female</custom>
    </customs>
  </list>
  <list list-id="0002">
    <first-name>first-name-2</first-name>
    <last-name>second-name-2</last-name>
    <customs>
      <custom attribute-id="gender">male</custom>
    </customs>
  </list>
</lists>

为什么在xml2js中处理嵌套元素时会发生此错误以及如何修复此错误？