title: type 'Null' is not a subtype of type 'Handler'
body: <p>I am using fluro: 2.0.3.</p>
  <p>I would like to do routing, but
  I get an error and can't resolve it.</p>
  <p>I changed Navigator.pushReplacementNamed and tried navigateTo, but it didn't solve the problem at all.</p>
  <p>I would appreciate it if you could tell me how to solve this problem.</p>
  <p>router.dart</p>
  <pre><code>class Router {
    final router = FluroRouter();
  
    static Handler _homeHandler = Handler(
        handlerFunc: (BuildContext? context, Map&lt;String, dynamic&gt; params) =&gt;
            HomePage());
  
      void setupRouter() {
      router.define(
        '/',
        handler: _homeHandler,
      );
    }
  }
  </code></pre>
  <p>main.dart</p>
  <pre><code>
  import 'package:flutter/material.dart';
  import 'package:tel_app/config/routes/routes.dart' as AppRouter;
  import 'package:tel_app/modules/screen/home.dart';
  import 'package:url_strategy/url_strategy.dart';
  
  void main() {
    AppRouter.Router().setupRouter();
    setPathUrlStrategy();
    runApp(App());
  }
  
  class App extends StatelessWidget {
    @override
    Widget build(BuildContext context) {
      return MaterialApp(
          title: 'App',
          home: HomePage(),
          initialRoute: '/',
          // Use the generator provided by Fluro package
          onGenerateRoute: AppRouter.Router().router.generator);
    }
  }
  </code></pre>
  <pre><code>class CustomBottomNavigationBar extends StatelessWidget {
    @override
    Widget build(BuildContext context) {
      return BottomNavigationBar(
        type: BottomNavigationBarType.fixed,
        onTap: (int index) {
          Navigator.pushReplacementNamed(context, '/');
        },
        items: const &lt;BottomNavigationBarItem&gt;[
          BottomNavigationBarItem(
            icon: Icon(Icons.dialpad),
            label: 'Home',
          ),
        ],
      );
    }
  }
  </code></pre>
  <p>error</p>
  <pre><code>The following _TypeError was thrown while handling a gesture:
  type 'Null' is not a subtype of type 'Handler'
  
  When the exception was thrown, this was the stack: 
  #0      FluroRouter.matchRoute (package:fluro/src/fluro_router.dart:143:13)
  #1      FluroRouter.generator (package:fluro/src/fluro_router.dart:278:9)
  #2      _WidgetsAppState._onGenerateRoute (package:flutter/src/widgets/app.dart:1221:37)
  #3      NavigatorState._routeNamed (package:flutter/src/widgets/navigator.dart:4155:46)
  #4      NavigatorState.pushReplacementNamed (package:flutter/src/widgets/navigator.dart:4280:35)
  
  </code></pre>