title: Scala: getting the key (and value) of a Map.head element
body: <p>Let's imagine the following immutable Map:</p>
  
  <pre><code>val foo = Map((10,"ten"), (100,"one hundred"))
  </code></pre>
  
  <p>I want to get the key of the first element.</p>
  
  <p><code>foo.head</code> gets the first element. But what next?</p>
  
  <p>I also want the value of this element, i.e. "ten"</p>