title: Flutter Navigator.pushNamed() custom route animation
body: <p>I want to use my <code>CustomPageRoute</code> in <code>Navigator.pushNamed()</code> but I can't find a way to use it. </p>
  
  <p>However, I can use it in following way</p>
  
  <pre><code>Navigator.push(context, CustomPageRoute(builder: (context) =&gt; MyPage()));
  </code></pre>
  
  <p>This is my route:</p>
  
  <pre><code>"/page": (context) =&gt; MyPage(), // Can I use CustomPageRoute here, if yes then how?
  </code></pre>