NERtcAudioRecordingCode constructor Null safety

1. nertc
2. nertc
3. NERtcAudioRecordingCode
4. NERtcAudioRecordingCode constructor

NERtcAudioRecordingCode class

1. Constructors
2. NERtcAudioRecordingCode
3. Properties
4. hashCode
5. runtimeType
6. Methods
7. noSuchMethod
8. toString
9. Operators
10. operator ==
11. Constants
12. error
13. errorSuffix
14. finish
15. openFileFailed
16. start