title: print the closure definition/source in Groovy
body: <p>Anyone who knows how the print the source of a closure in Groovy?</p>
  
  <p>For example, I have this closure (binded to <code>a</code>)</p>
  
  <pre><code>def a = { it.twice() } 
  </code></pre>
  
  <p>I would like to have the <code>String</code>  "it.twice()" or "{ it.twice() }"</p>
  
  <p>Just a simple <code>toString</code> ofcourse won't work:</p>
  
  <pre><code>a.toString(); //results in: Script1$_run_closure1_closure4_closure6@12f1bf0
  </code></pre>