title: Axon retry testing
body: <p>I'm writing a system using the Axon framework. One of my event handlers posts a command to a different microservice and I have implemented the retry function with exponential back-off to deal with the other service not being available. </p>
  
  <p>I can see this working if I manually turn off the receiving microservice on watch the logs etc, but is there a more formal way of automating this testing? </p>