NoSuchMethodError: метод «привод» был вызван при нулевом значении

Я знаю, что есть довольно много вопросов с заголовком, напоминающим NoSuchMethodError: The method '#**something**#' was called on null. И обычно эта проблема возникает, когда вы пытаетесь получить доступ к методу нулевого объекта. Но в моем случае это исключение отображается, когда я пытаюсь добавить следующий код в свой StatefulWidget:

 _handleMyBusinessesTap() {
    Navigator.of(context).push(
    MaterialPageRoute(
      builder: (context) => PageBusinessList(
           firebaseUser: widget.firebaseUser,
      ),
    ),
  );
}

Как только я пытаюсь использовать объект Navigator в своем коде, я получаю это исключение. Единственное отличие, которое я могу придумать на этой странице, от других страниц, на которых объект Navigator не вызывает никаких проблем, заключается в том, что я строю свою страницу следующим образом:

 Widget build(BuildContext context) {
  return DefaultTabController(
    length: 3,
    child: Scaffold(
      appBar: _buildAppBar(),
      drawer: _buildDrawer(),
      body: _buildBody(),
    ),
  );
}

Я использую здесь DefaultTabController содержит тело из 3 страниц:

 Widget _buildBody() {
  return TabBarView(
    children: [
      MyCardScreen(),
      ReceivedScreen(),
      SentScreen(),
    ],
  );
}

Метод _handleMyBusinessesTap — это один из вариантов, которые у меня есть в ящике, и я хочу перейти на новую страницу, но по какой-то причине, когда я добавляю его, он выдает это исключение в заголовке. Кто-нибудь сталкивался с этой проблемой и знает, как с ней бороться?

вот метод buildDrawer:

 Widget _buildDrawer() {
return Drawer(
  child: ListView(
    padding: EdgeInsets.zero,
    children: <Widget>[
      UserAccountsDrawerHeader(
        accountName: _buildAccountNameWidget(),
        accountEmail: _buildAccountEmailWidget(),
        currentAccountPicture: _buildAccountCircleAvatar(),
      ),
      ListTile(title: Text("My Default Business Card"), onTap: _handleMyDefaultBusinessCardTap()),
      ListTile(title: Text("My Businesses"), onTap: _handleMyBusinessesTap()),
      ListTile(title: Text("Terms and Conditions"), onTap: _handleTermsAndConditionsTap()),
      ListTile(title: Text("Privacy Policy"), onTap: _handlePrivacyPolicyTap()),
      ListTile(title: Text("Log Out"), onTap: _handleLogOutTap()),
    ],
  ),
);
}

вот остальная часть стека:

I/flutter (  722): ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
I/flutter (  722): The following assertion was thrown building PageMain(dirty, dependencies: [_InheritedTheme,
I/flutter (  722): _LocalizationsScope-[GlobalKey#b039d]], state: _PageMainWidgetState#e33af):
I/flutter (  722): setState() or markNeedsBuild() called during build.
I/flutter (  722): This Overlay widget cannot be marked as needing to build because the framework is already in the
I/flutter (  722): process of building widgets. A widget can be marked as needing to be built during the build phase
I/flutter (  722): only if one of its ancestors is currently building. This exception is allowed because the framework
I/flutter (  722): builds parent widgets before children, which means a dirty descendant will always be built.
I/flutter (  722): Otherwise, the framework might not visit this widget during this build phase.
I/flutter (  722): The widget on which setState() or markNeedsBuild() was called was:
I/flutter (  722):   Overlay-[LabeledGlobalKey<OverlayState>#51a6b](state: OverlayState#7d0ac(entries:
I/flutter (  722):   [OverlayEntry#f42cb(opaque: false; maintainState: false), OverlayEntry#d6b18(opaque: false;
I/flutter (  722):   maintainState: true), OverlayEntry#75d78(opaque: false; maintainState: false),
I/flutter (  722):   OverlayEntry#02406(opaque: false; maintainState: true), OverlayEntry#8f4e5(opaque: false;
I/flutter (  722):   maintainState: false), OverlayEntry#11c40(opaque: false; maintainState: true)]))
I/flutter (  722): The widget which was currently being built when the offending call was made was:
I/flutter (  722):   PageMain(dirty, dependencies: [_InheritedTheme, _LocalizationsScope-[GlobalKey#b039d]], state:
I/flutter (  722):   _PageMainWidgetState#e33af) 
I/flutter (  722): When the exception was thrown, this was the stack:
I/flutter (  722): #0      Element.markNeedsBuild.<anonymous closure> (package:flutter/src/widgets/framework.dart:3503:11)
I/flutter (  722): #1      Element.markNeedsBuild (package:flutter/src/widgets/framework.dart:3529:6)
I/flutter (  722): #2      State.setState (package:flutter/src/widgets/framework.dart:1133:14)
I/flutter (  722): #3      OverlayState.insertAll (package:flutter/src/widgets/overlay.dart:346:5)
I/flutter (  722): #4      OverlayRoute.install (package:flutter/src/widgets/routes.dart:43:24)
I/flutter (  722): #5      TransitionRoute.install (package:flutter/src/widgets/routes.dart:180:11)
I/flutter (  722): #6      ModalRoute.install (package:flutter/src/widgets/routes.dart:895:11)
I/flutter (  722): #7      NavigatorState.push (package:flutter/src/widgets/navigator.dart:1742:11)
I/flutter (  722): #8      _PageMainWidgetState._handleMyBusinessesTap (package:bizooc_client/pages/page_main.dart:86:27)
I/flutter (  722): #9      _PageMainWidgetState._buildDrawer (package:bizooc_client/pages/page_main.dart:60:57)
I/flutter (  722): #10     _PageMainWidgetState.build (package:bizooc_client/pages/page_main.dart:33:17)
I/flutter (  722): #11     StatefulElement.build (package:flutter/src/widgets/framework.dart:3825:27)
I/flutter (  722): #12     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3739:15)
I/flutter (  722): #13     Element.rebuild (package:flutter/src/widgets/framework.dart:3565:5)
I/flutter (  722): #14     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3722:5)
I/flutter (  722): #15     StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3864:11)
I/flutter (  722): #16     ComponentElement.mount (package:flutter/src/widgets/framework.dart:3717:5)
I/flutter (  722): #17     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2961:14)
I/flutter (  722): #18     Element.updateChild (package:flutter/src/widgets/framework.dart:2764:12)
I/flutter (  722): #19     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4876:14)
I/flutter (  722): #20     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2961:14)
I/flutter (  722): #21     Element.updateChild (package:flutter/src/widgets/framework.dart:2764:12)
I/flutter (  722): #22     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3750:16)
I/flutter (  722): #23     Element.rebuild (package:flutter/src/widgets/framework.dart:3565:5)
I/flutter (  722): #24     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3722:5)
I/flutter (  722): #25     ComponentElement.mount (package:flutter/src/widgets/framework.dart:3717:5)
I/flutter (  722): #26     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2961:14)
I/flutter (  722): #27     Element.updateChild (package:flutter/src/widgets/framework.dart:2764:12)
I/flutter (  722): #28     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4876:14)
I/flutter (  722): #29     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2961:14)
I/flutter (  722): #30     Element.updateChild (package:flutter/src/widgets/framework.dart:2764:12)
I/flutter (  722): #31     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4876:14)
I/flutter (  722): #32     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2961:14)
I/flutter (  722): #33     Element.updateChild (package:flutter/src/widgets/framework.dart:2764:12)
I/flutter (  722): #34     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4876:14)
I/flutter (  722): #35     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2961:14)
I/flutter (  722): #36     Element.updateChild (package:flutter/src/widgets/framework.dart:2764:12)
I/flutter (  722): #37     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4876:14)
I/flutter (  722): #38     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2961:14)
I/flutter (  722): #39     Element.updateChild (package:flutter/src/widgets/framework.dart:2764:12)
I/flutter (  722): #40     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3750:16)
I/flutter (  722): #41     Element.rebuild (package:flutter/src/widgets/framework.dart:3565:5)
I/flutter (  722): #42     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3722:5)
I/flutter (  722): #43     StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3864:11)
I/flutter (  722): #44     ComponentElement.mount (package:flutter/src/widgets/framework.dart:3717:5)
I/flutter (  722): #45     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2961:14)
I/flutter (  722): #46     Element.updateChild (package:flutter/src/widgets/framework.dart:2764:12)
I/flutter (  722): #47     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3750:16)
I/flutter (  722): #48     Element.rebuild (package:flutter/src/widgets/framework.dart:3565:5)
I/flutter (  722): #49     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3722:5)
I/flutter (  722): #50     ComponentElement.mount (package:flutter/src/widgets/framework.dart:3717:5)
I/flutter (  722): #51     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2961:14)
I/flutter (  722): #52     Element.updateChild (package:flutter/src/widgets/framework.dart:2764:12)
I/flutter (  722): #53     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3750:16)
I/flutter (  722): #54     Element.rebuild (package:flutter/src/widgets/framework.dart:3565:5)
I/flutter (  722): #55     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3722:5)
I/flutter (  722): #56     StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3864:11)
I/flutter (  722): #57     ComponentElement.mount (package:flutter/src/widgets/framework.dart:3717:5)
I/flutter (  722): #58     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2961:14)
I/flutter (  722): #59     Element.updateChild (package:flutter/src/widgets/framework.dart:2764:12)
I/flutter (  722): #60     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4876:14)
I/flutter (  722): #61     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2961:14)
I/flutter (  722): #62     Element.updateChild (package:flutter/src/widgets/framework.dart:2764:12)
I/flutter (  722): #63     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3750:16)
I/flutter (  722): #64     Element.rebuild (package:flutter/src/widgets/framework.dart:3565:5)
I/flutter (  722): #65     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3722:5)
I/flutter (  722): #66     ComponentElement.mount (package:flutter/src/widgets/framework.dart:3717:5)
I/flutter (  722): #67     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2961:14)
I/flutter (  722): #68     Element.updateChild (package:flutter/src/widgets/framework.dart:2764:12)
I/flutter (  722): #69     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4876:14)
I/flutter (  722): #70     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2961:14)
I/flutter (  722): #71     Element.updateChild (package:flutter/src/widgets/framework.dart:2764:12)
I/flutter (  722): #72     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3750:16)
I/flutter (  722): #73     Element.rebuild (package:flutter/src/widgets/framework.dart:3565:5)
I/flutter (  722): #74     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3722:5)
I/flutter (  722): #75     StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3864:11)
I/flutter (  722): #76     ComponentElement.mount (package:flutter/src/widgets/framework.dart:3717:5)
I/flutter (  722): #77     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2961:14)
I/flutter (  722): #78     Element.updateChild (package:flutter/src/widgets/framework.dart:2764:12)
I/flutter (  722): #79     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3750:16)
I/flutter (  722): #80     Element.rebuild (package:flutter/src/widgets/framework.dart:3565:5)
I/flutter (  722): #81     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3722:5)
I/flutter (  722): #82     ComponentElement.mount (package:flutter/src/widgets/framework.dart:3717:5)
I/flutter (  722): #83     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2961:14)
I/flutter (  722): #84     Element.updateChild (package:flutter/src/widgets/framework.dart:2764:12)
I/flutter (  722): #85     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4876:14)
I/flutter (  722): #86     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2961:14)
I/flutter (  722): #87     Element.updateChild (package:flutter/src/widgets/framework.dart:2764:12)
I/flutter (  722): #88     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3750:16)
I/flutter (  722): #89     Element.rebuild (package:flutter/src/widgets/framework.dart:3565:5)
I/flutter (  722): #90     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3722:5)
I/flutter (  722): #91     ComponentElement.mount (package:flutter/src/widgets/framework.dart:3717:5)
I/flutter (  722): #92     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2961:14)
I/flutter (  722): #93     Element.updateChild (package:flutter/src/widgets/framework.dart:2764:12)
I/flutter (  722): #94     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3750:16)
I/flutter (  722): #95     Element.rebuild (package:flutter/src/widgets/framework.dart:3565:5)
I/flutter (  722): #96     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3722:5)
I/flutter (  722): #97     StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3864:11)
I/flutter (  722): #98     ComponentElement.mount (package:flutter/src/widgets/framework.dart:3717:5)
I/flutter (  722): #99     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2961:14)
I/flutter (  722): #100    Element.updateChild (package:flutter/src/widgets/framework.dart:2764:12)
I/flutter (  722): #101    ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3750:16)
I/flutter (  722): #102    Element.rebuild (package:flutter/src/widgets/framework.dart:3565:5)
I/flutter (  722): #103    ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3722:5)
I/flutter (  722): #104    StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3864:11)
I/flutter (  722): #105    ComponentElement.mount (package:flutter/src/widgets/framework.dart:3717:5)
I/flutter (  722): #106    Element.inflateWidget (package:flutter/src/widgets/framework.dart:2961:14)
I/flutter (  722): #107    Element.updateChild (package:flutter/src/widgets/framework.dart:2764:12)
I/flutter (  722): #108    RenderObjectElement.updateChildren (package:flutter/src/widgets/framework.dart:4659:32)
I/flutter (  722): #109    MultiChildRenderObjectElement.update (package:flutter/src/widgets/framework.dart:4992:17)
I/flutter (  722): #110    Element.updateChild (package:flutter/src/widgets/framework.dart:2753:15)
I/flutter (  722): #111    _TheatreElement.update (package:flutter/src/widgets/overlay.dart:607:16)
I/flutter (  722): #112    Element.updateChild (package:flutter/src/widgets/framework.dart:2753:15)
I/flutter (  722): #113    ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3750:16)
I/flutter (  722): #114    Element.rebuild (package:flutter/src/widgets/framework.dart:3565:5)
I/flutter (  722): #115    StatefulElement.update (package:flutter/src/widgets/framework.dart:3894:5)
I/flutter (  722): #116    Element.updateChild (package:flutter/src/widgets/framework.dart:2753:15)
I/flutter (  722): #117    ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3750:16)
I/flutter (  722): #118    Element.rebuild (package:flutter/src/widgets/framework.dart:3565:5)
I/flutter (  722): #119    ProxyElement.update (package:flutter/src/widgets/framework.dart:4006:5)
I/flutter (  722): #120    Element.updateChild (package:flutter/src/widgets/framework.dart:2753:15)
I/flutter (  722): #121    SingleChildRenderObjectElement.update (package:flutter/src/widgets/framework.dart:4883:14)
I/flutter (  722): #122    Element.updateChild (package:flutter/src/widgets/framework.dart:2753:15)
I/flutter (  722): #123    ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3750:16)
I/flutter (  722): #124    Element.rebuild (package:flutter/src/widgets/framework.dart:3565:5)
I/flutter (  722): #125    StatefulElement.update (package:flutter/src/widgets/framework.dart:3894:5)
I/flutter (  722): #126    Element.updateChild (package:flutter/src/widgets/framework.dart:2753:15)
I/flutter (  722): #127    SingleChildRenderObjectElement.update (package:flutter/src/widgets/framework.dart:4883:14)
I/flutter (  722): #128    Element.updateChild (package:flutter/src/widgets/framework.dart:2753:15)
I/flutter (  722): #129    SingleChildRenderObjectElement.update (package:flutter/src/widgets/framework.dart:4883:14)
I/flutter (  722): #130    Element.updateChild (package:flutter/src/widgets/framework.dart:2753:15)
I/flutter (  722): #131    ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3750:16)
I/flutter (  722): #132    Element.rebuild (package:flutter/src/widgets/framework.dart:3565:5)
I/flutter (  722): #133    BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:2278:33)
I/flutter (  722): #134    _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding&WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:700:20)
I/flutter (  722): #135    _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:286:5)
I/flutter (  722): #136    _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1012:15)
I/flutter (  722): #137    _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:952:9)
I/flutter (  722): #138    _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._handleDrawFrame (package:flutter/src/scheduler/binding.dart:864:5)
I/flutter (  722): #142    _invoke (dart:ui/hooks.dart:219:10)
I/flutter (  722): #143    _drawFrame (dart:ui/hooks.dart:178:3)
I/flutter (  722): (elided 3 frames from package dart:async)
I/flutter (  722): ════════════════════════════════════════════════════════════════════════════════════════════════════
I/flutter (  722): Another exception was thrown: NoSuchMethodError: The getter 'status' was called on null.
I/flutter (  722): Another exception was thrown: NoSuchMethodError: The method 'drive' was called on null.