title: how to get values from a const object?
body: <p>I created a const object at app.config.dart with the following code:</p>
  
  <pre><code>const configObj = const {
   'webServer': const {
     'appBaseHref' : "/"
   },
   'auth0': const {
     'apiKey': "foo",
     'domain': "bar",
     'callbackUrl': "callback"
   }
  };
  </code></pre>
  
  <p>now in my main dart file I import the <code>app.config.dart</code> and I try to get the values there and now idea how to do that. <code>configObj.auth0.apiKey</code> produces the error <code>EXCEPTION: Class 'ImmutableMap' has no instance getter 'auth0'</code>. </p>
  
  <p>so how do I do this ?</p>
  
  <p>thanks!</p>