flutter_math_fork null check error

[aelayyuu]

flutter_math_fork null error shown as bellow

/opt/hostedtoolcache/flutter/3.0.5-stable/x64/.pub-cache/hosted/pub.dartlang.org/flutter_math_fork-0.5.0/lib/src/widgets/selectable.dart:459:24: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.

'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('/opt/hostedtoolcache/flutter/3.0.5-stable/x64/packages/flutter/lib/src/scheduler/binding.dart').
SchedulerBinding.instance!.addPostFrameCallback((_) {
^
/opt/hostedtoolcache/flutter/3.0.5-stable/x64/.pub-cache/hosted/pub.dartlang.org/flutter_math_fork-0.5.0/lib/src/widgets/selection/overlay_manager.dart:138:28: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('/opt/hostedtoolcache/flutter/3.0.5-stable/x64/packages/flutter/lib/src/scheduler/binding.dart').
if (SchedulerBinding.instance!.schedulerPhase ==
^
/opt/hostedtoolcache/flutter/3.0.5-stable/x64/.pub-cache/hosted/pub.dartlang.org/flutter_math_fork-0.5.0/lib/src/widgets/selection/overlay_manager.dart:140:26: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('/opt/hostedtoolcache/flutter/3.0.5-stable/x64/packages/flutter/lib/src/scheduler/binding.dart').
SchedulerBinding.instance!
^
/opt/hostedtoolcache/flutter/3.0.5-stable/x64/.pub-cache/hosted/pub.dartlang.org/flutter_math_fork-0.5.0/lib/src/widgets/selection/web_selection_manager.dart:119:24: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('/opt/hostedtoolcache/flutter/3.0.5-stable/x64/packages/flutter/lib/src/scheduler/binding.dart').
SchedulerBinding.instance!
^
/opt/hostedtoolcache/flutter/3.0.5-stable/x64/.pub-cache/hosted/pub.dartlang.org/flutter_math_fork-0.5.0/lib/src/widgets/selection/overlay.dart:141:26: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('/opt/hostedtoolcache/flutter/3.0.5-stable/x64/packages/flutter/lib/src/scheduler/binding.dart').
if (SchedulerBinding.instance!.schedulerPhase ==
^
/opt/hostedtoolcache/flutter/3.0.5-stable/x64/.pub-cache/hosted/pub.dartlang.org/flutter_math_fork-0.5.0/lib/src/widgets/selection/overlay.dart:143:24: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('/opt/hostedtoolcache/flutter/3.0.5-stable/x64/packages/flutter/lib/src/scheduler/binding.dart').
SchedulerBinding.instance!.addPostFrameCallback(_markNeedsBuild);
^
/opt/hostedtoolcache/flutter/3.0.5-stable/x64/.pub-cache/hosted/pub.dartlang.org/flutter_math_fork-0.5.0/lib/src/widgets/selection/overlay.dart:193:26: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('/opt/hostedtoolcache/flutter/3.0.5-stable/x64/packages/flutter/lib/src/scheduler/binding.dart').
if (SchedulerBinding.instance!.schedulerPhase ==
^
/opt/hostedtoolcache/flutter/3.0.5-stable/x64/.pub-cache/hosted/pub.dartlang.org/flutter_math_fork-0.5.0/lib/src/widgets/selection/overlay.dart:195:24: Warning: Operand of null-aware operation '!' has type 'SchedulerBinding' which excludes null.
'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('/opt/hostedtoolcache/flutter/3.0.5-stable/x64/packages/flutter/lib/src/scheduler/binding.dart').
SchedulerBinding.instance!.addPostFrameCallback(_markNeedsBuild);