title: How do I set a default choice in jenkins pipeline?
body: <p>quite frustrating I can't find an example of this. How do I set the default choice?</p>
  
  <pre class="lang-groovy prettyprint-override"><code>parameters {
      choice(
          defaultValue: 'bbb',
          name: 'param1',
          choices: 'aaa\nbbb\nccc',
          description: 'lkdsjflksjlsjdf'
      )
  }
  </code></pre>
  
  <p>defaultValue is not valid here. I want the choice to be optional and a default value to be set if the pipeline is run non-manually (via a commit).</p>