title: Flutter: Warning: Operand of null-aware operation '!' has type 'WidgetsBinding' which excludes null. when upgrading to flutter 3.0.0
body: <p>When upgraded to flutter 3.0.0 , there is a problem started to appear when running the app,</p>
  <p>(The app works but there are error/s (warning/s) in the terminal).</p>
  <p>It seems like a Binding issue.</p>
  <p>the error(warning) says:
  Warning:  Operand of null-aware operation '!' has type 'WidgetsBinding' which excludes null.</p>
  <pre><code>: Warning: Operand of null-aware operation '!' has type 'WidgetsBinding' which excludes null.
  ../…/src/keyboard_visibility.dart:21
  - 'WidgetsBinding' is from 'package:flutter/src/widgets/binding.dart' ('../../../fvm/versions/3.0.0/packages/flutter/lib/src/widgets/binding.dart').
  package:flutter/…/widgets/binding.dart:1
      WidgetsBinding.instance!.addObserver(this);
  
                     ^
  : Warning: Operand of null-aware operation '!' has type 'WidgetsBinding' which excludes null.
  ../…/src/keyboard_visibility.dart:37
  - 'WidgetsBinding' is from 'package:flutter/src/widgets/binding.dart' ('../../../fvm/versions/3.0.0/packages/flutter/lib/src/widgets/binding.dart').
  package:flutter/…/widgets/binding.dart:1
      WidgetsBinding.instance!.removeObserver(this);
                     ^
  : Warning: Operand of null-aware operation '!' has type 'WidgetsBinding' which excludes null.
  ../…/src/bot_toast_init.dart:15
  - 'WidgetsBinding' is from 'package:flutter/src/widgets/binding.dart' ('../../../fvm/versions/3.0.0/packages/flutter/lib/src/widgets/binding.dart').
  package:flutter/…/widgets/binding.dart:1
      WidgetsBinding.instance!.addObserver(this);
                     ^
  : Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
  ../…/src/bot_toast_manager.dart:6
  - 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('../../../fvm/versions/3.0.0/packages/flutter/lib/src/scheduler/binding.dart').
  package:flutter/…/scheduler/binding.dart:1
    SchedulerBinding.instance!.addPostFrameCallback((_) {
                     ^
  : Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
  ../…/src/bot_toast_manager.dart:9
  - 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('../../../fvm/versions/3.0.0/packages/flutter/lib/src/scheduler/binding.dart').
  package:flutter/…/scheduler/binding.dart:1
    SchedulerBinding.instance!.ensureVisualUpdate();
  </code></pre>
  <p><strong>Edit:</strong>
  <strong>- The problem is related to the compatibility of some packages with the flutter 3.0.0</strong></p>
  <ul>
  <li>(There are some changes in flutter 3, so now authors of the packages should be catching up for these changes).</li>
  </ul>
  <p><a href="https://docs.flutter.dev/development/tools/sdk/release-notes/release-notes-3.0.0#if-you-see-warnings-about-bindings" rel="noreferrer">Flutter 3.0.0 release notes</a></p>
  <blockquote>
  <p>f you see warnings about bindings
  When migrating to Flutter 3, you might see warnings like the following:</p>
  </blockquote>
  <blockquote>
  <p><code>Warning: Operand of null-aware operation '!' has type &gt;'SchedulerBinding' which excludes null.</code></p>
  </blockquote>
  <p>-<strong>for example like the package  <a href="https://pub.dev/packages/bot_toast" rel="noreferrer">bot_toast</a>
  There is an open issue on the GitHub repository of this package
  <a href="https://github.com/MMMzq/bot_toast/issues/133" rel="noreferrer">https://github.com/MMMzq/bot_toast/issues/133</a>
  so the problem should be fixed soon after releasing an update as they said.</strong></p>