这是错误
E/flutter (24762): [ERROR:flutter/shell/common/shell.cc(184)] Dart Error: Unhandled exception:
E/flutter (24762): NoSuchMethodError: The method 'group' was called on null.
E/flutter (24762): Receiver: null
E/flutter (24762): Tried calling: group(1)
E/flutter (24762): #0 Object.noSuchMethod (dart:core-patch/object_patch.dart:50:5)
E/flutter (24762): #1 PlayerSourceParser.parseCipherOperations (package:youtube_extractor/src/internal/parsers/player_source_parser.dart:23:27)
E/flutter (24762): #2 YouTubeExtractor._getVideoPlayerSourceAsync (package:youtube_extractor/youtube_extractor.dart:298:29)
E/flutter (24762):
E/flutter (24762): #3 YouTubeExtractor.getMediaStreamsAsync (package:youtube_extractor/youtube_extractor.dart:73:19)
E/flutter (24762):
E/flutter (24762): #4 test (package:chewie_sample/geturl.dart:8:40)
E/flutter (24762):
E/flutter (24762): #5 MyApp.build (package:chewie_sample/main.dart:15:5)
E/flutter (24762): #6 StatelessElement.build (package:flutter/src/widgets/framework.dart:3789:28)
E/flutter (24762): #7 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3739:15)
E/flutter (24762): #8 Element.rebuild (package:flutter/src/widgets/framework.dart:3565:5)
E/flutter (24762): #9 BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:2278:33)
E/flutter (24762): #10 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding&WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:700:20)
E/flutter (24762): #11 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:286:5)
E/flutter (24762): #12 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1012:15)
E/flutter (24762): #13 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:952:9)
E/flutter (24762): #14 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.scheduleWarmUpFrame. (package:flutter/src/scheduler/binding.dart:773:7)
E/flutter (24762): #15 Timer._createTimer. (dart:async-patch/timer_patch.dart:21:15)
E/flutter (24762): #16 _Timer._runTimers (dart:isolate-patch/timer_impl.dart:382:19)
E/flutter (24762): #17 _Timer._handleMessage (dart:isolate-patch/timer_impl.dart:416:5)
E/flutter (24762): #18 _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:171:12)