title: Camel / AggregationStrategy after tokenizeXML
body: <p>I want to know the number of order saved after split().tokenizeXML</p>
  
  <p>i have a xml</p>
  
  <pre><code>&lt;orders&gt;
   &lt;order&gt;
   ....
  </code></pre>
  
  <p>my route</p>
  
  <pre><code>.split().tokenizeXML("order")
   .unmarshal("xmlbsondataformat")
   .beanRef("orderShopConnector", "saveOrder")
  </code></pre>
  
  <p>in my bean orderShopConnector, i add in header properties saveOK=1.</p>
  
  <pre><code>headers.put("ordersave",1);
  </code></pre>
  
  <p>now, I want know the sum of the order saved, in the firstexchange properties.
  I think use AggregationStrategy but i canot see how to use after tokenizeXML, it is possible?</p>