title: Understanding the match operator
body: <p>Hi I am confused about the usage of the match operator. I have come across a snippet of code that looks nothing like the explanation on the documentation: <a href="https://docs.mulesoft.com/mule-runtime/3.9/dataweave-operators#match" rel="nofollow noreferrer">https://docs.mulesoft.com/mule-runtime/3.9/dataweave-operators#match</a></p>
  
  <pre><code>%function testMatch(key)
      (key match {
          x when x is :null -&gt; false,
          x when x == "A" -&gt; true, 
          x when x == "B" -&gt; false, 
          x when x == "J" -&gt; true, 
          x when x == "K" -&gt; false, 
          x when x == "L" -&gt; true, 
          default -&gt; false
      })
  </code></pre>
  
  <p>Please help understand the meaning of this syntax for match</p>