OutputStreamBase constructor Null safety

1. Flutter
2. archive_io
3. OutputStreamBase
4. OutputStreamBase constructor

OutputStreamBase class

1. Constructors
2. OutputStreamBase
3. Properties
4. hashCode
5. length
6. runtimeType
7. Methods
8. flush
9. noSuchMethod
10. toString
11. writeByte
12. writeBytes
13. writeInputStream
14. writeUint16
15. writeUint32
16. Operators
17. operator ==