title: Running a scopt option with no values
body: <p>I am writing a CLI in Scala using Scopt.</p>
  
  <p>I would like to add in the ability to call a command with or without the values.</p>
  
  <p>For example:</p>
  
  <pre><code>CliUtility -o &lt;value&gt; &lt;value&gt; &lt;value&gt;
  </code></pre>
  
  <p>Would send in a Seq[String] of the values.</p>
  
  <p>I want to also be able to run -o</p>
  
  <pre><code>CliUtility -o
  </code></pre>
  
  <p>I want that to send an empty Seq[String] but I can't see how to handle this.</p>
  
  <p>Thank you.</p>