title: How to mock dynamic (toD) endpoint
body: <p>Hy all,</p>
  
  <p>suppose I have to following production code:</p>
  
  <pre><code>from("file:/home/test/from/")
    .setHeader("targetDynamicEndpoint", constant("file:/home/test/to/"))
    .toD("${header.targetDynamicEndpoint}")
  </code></pre>
  
  <p>How would I be able to mock the producer endpoint ('toD')?</p>
  
  <p>I would be able to guess the string passed to the 'toD', because its set via StringBoot properties</p>