title: How can I split up a String in Dart and add dashes in between? (Flutter, Dart, Strings, Formatting)
body: <p>I have these types of UIDs here:</p>
  <pre><code>c4VTSVn3JfUxx9durORzj33UHfA2
  </code></pre>
  <p>and now I would like to receive this in my Dart code in Flutter:</p>
  <pre><code>c4VTSVn3-JfUx-x9du-rORz-j33UHfA2
  </code></pre>
  <p>I am looking for a way to split up strings in the UID-format and put it together again with the dashes in between.
  How can I do that?</p>