title: Groovy Method to combine list of lists
body: <pre><code>Input &gt;&gt; list = [[1,2,3], [6], [3,4,5,6]]
  
  Output &gt;&gt; [1,2,3,3,4,5,6,6] 
  </code></pre>
  
  <p>I want to know if there is something more straightforward than this</p>
  
  <pre><code>l = []
  list.each{ l = l + it }
  println l
  </code></pre>
  
  <p>like a default groovy closure or method?</p>