title: The constructor being called isn't
body: <p>I have a class which I intend to use in another class a default parameter.</p>
  <pre class="lang-dart prettyprint-override"><code>import 'package:permission_handler/permission_handler.dart';
  
  /// Service to handle requesting of permissions.
  /// Using extension methods disables testing
  class PermissionService {
    /// Check the status of a specific [Permission]
    Future&lt;PermissionStatus&gt; status(Permission permission) {
      return permission.status;
    }
  
    /// Open the app settings.
    Future&lt;bool&gt; openAppSettings() {
      return openAppSettings();
    }
  
    /// Request permissions for a single permission.
    Future&lt;PermissionStatus&gt; request(Permission permission) {
      return permission.request();
    }
  }
  
  </code></pre>
  <p>But I am getting this error below.</p>
  <pre class="lang-dart prettyprint-override"><code>const permissionService = PermissionService(); 
  // The constructor being called isn't a const constructor.
  // Try removing 'const' from the constructor invocation.
  </code></pre>
  <p>Why can't I create the class as a const?</p>