title: Logback placeholders not working with tests
body: <p>I have code with lines of logs, which looked like:</p>
  
  <pre><code>log.info("Message received with ID :"+ messageId);
  </code></pre>
  
  <p>I need change all concat to logback-style with placeholders.</p>
  
  <pre><code>log.info("Message received with ID :{}", messageId);
  </code></pre>
  
  <p>It works fine, when I see logs they are OK. I also have tests based on logging, I write expectation messages, then send message it passes through logic and I check, if logs are the same as expected. <a href="http://www.infoq.com/articles/Utilizing-Logging" rel="nofollow">http://www.infoq.com/articles/Utilizing-Logging</a>. When I had concat style logs, everythings was good, but now I don't see values, I see brackets {} in this tests, and they all fail.
  so, application gives me:</p>
  
  <pre><code>Message received with ID : 32145
  </code></pre>
  
  <p>but tests give me:</p>
  
  <pre><code>Message received with ID :{}
  </code></pre>
  
  <p>Does anyone have the same problem and how it could be fixed? Please help me. Thanks.</p>