title: Flutter: Define custom TextStyles for use throughout the app
body: <p>How can I define a small set of custom TextStyles that can then be reused throughout my app. The custom TextStyles should be based on the TextStyles defined in the Theme.</p>
  
  <p>I know how to create the individual TextStyles (e.g.)</p>
  
  <pre><code>Theme.of(context).textTheme.title.copyWith(fontWeight: FontWeight.bold,)
  </code></pre>