title: NodeJS xml-stream, parsing unknown nodes
body: <p>I need a powerful package to parse large XML files, and I came across <a href="https://www.npmjs.com/package/xml-stream" rel="nofollow noreferrer">xml-stream</a>. 
  It is great, but for some reason I can't seem to find how to parse unknown nodes, it expects me to send the expected field as a parameter.</p>
  
  <p>That's the XML file</p>
  
  <pre><code>&lt;Offers&gt;
  &lt;Offer&gt;
      &lt;Model&gt;
          694547
      &lt;/Model&gt;
      &lt;RegularPrice&gt;
          219.00
      &lt;/RegularPrice&gt;
      &lt;ParentSKU&gt;
          654987
      &lt;/ParentSKU&gt;
  &lt;/Offer&gt;
  &lt;Offer&gt;
      &lt;Model&gt;
          694548
      &lt;/Model&gt;
      &lt;RegularPrice&gt;
          235.00
      &lt;/RegularPrice&gt;
      &lt;ParentSKU&gt;
          123456
      &lt;/ParentSKU&gt;
  &lt;/Offer&gt;
  </code></pre>
  
  <p></p>
  
  <p>And this is the code I use</p>
  
  <pre><code>var XmlStream = require('xml-stream'); 
  var fs = require('fs');
  
  var stream = fs.createReadStream(filePath);
  var xml = new XmlStream(stream);
  
  xml.on('endElement: Offer', function (item) { //&lt;&lt;&lt;- Here I need to add 'Offer' as an expected node
      console.log('loaded', JSON.stringify(item));
  });
  
  xml.on('end', function () {
      console.log('END XML');
  });
  </code></pre>
  
  <p>The response is great, as expected</p>
  
  <pre><code>loaded {"Model":"694547","RegularPrice":"219.00","ParentSKU":"654987"}
  loaded {"Model":"694548","RegularPrice":"235.00","ParentSKU":"123456"}
  END XML
  </code></pre>
  
  <p>How can I get the same list without me having to set 'Offer' as an expected node? 
  The XML's I'm expecting to get can have different nodes and values. </p>