title: toString in logback
body: <p>I am using logback in our project. I have gone through the links for logback for curly braces. </p>
  
  <pre><code>logger.debug(" My class output value - {}, object toString() {}", object.value(), object.toString());
  </code></pre>
  
  <p>Debug is not enabled in my project. We saw the toString() is getting called in our project which impact our performance. Will the toString() be called during the code execution with debug disabled?</p>
  
  <p>Can i use toString() with this approach? Because as per curly braces definition string concat will not happen. Will it be only for string concat or is that applicable for method calls too?</p>