method 'setMockMethodCallHandler' isn't defined ; & The getter 'subhead' and 'body2' isn't defined for the class 'TextTheme'.

[RajuNarula369]

/C:/src/flutter/flutter/.pub-cache/hosted/pub.dartlang.org/shared_preferences-0.4.3/lib/shared_preferences.dart:146:15:
Error: The method 'setMockMethodCallHandler' isn't defined for the class 'MethodChannel'.

• 'MethodChannel' is from 'package:flutter/src/services/platform_channel.dart' ('/C:/src/flutter/flutter/packages/flutter/lib/src/services/platform_channel.dart').
  Try correcting the name to the name of an existing method, or defining a method named 'setMockMethodCallHandler'.
  _kChannel.setMockMethodCallHandler((MethodCall methodCall) async {
  ^^^^^^^^^^^^^^^^^^^^^^^^
  lib/tabs.dart:206:32: Error: The getter 'body2' isn't defined for the class 'TextTheme'.
• 'TextTheme' is from 'package:flutter/src/material/text_theme.dart' ('/C:/src/flutter/flutter/packages/flutter/lib/src/material/text_theme.dart').
  Try correcting the name to the name of an existing getter, or defining a getter or field named 'body2'.
  .body2
  ^^^^^
  lib/tabs.dart:288:62: Error: The getter 'subhead' isn't defined for the class 'TextTheme'.
• 'TextTheme' is from 'package:flutter/src/material/text_theme.dart' ('/C:/src/flutter/flutter/packages/flutter/lib/src/material/text_theme.dart').
  Try correcting the name to the name of an existing getter, or defining a getter or field named 'subhead'.
  style: Theme.of(context).textTheme.subhead,
  ^^^^^^^