APITypeCodec constructor Null safety

1. conduit_open_api
2. open_api_v3
3. APITypeCodec
4. APITypeCodec constructor

APITypeCodec class

1. Constructors
2. APITypeCodec
3. Properties
4. hashCode
5. runtimeType
6. Methods
7. noSuchMethod
8. toString
9. Operators
10. operator ==
11. Static methods
12. decode
13. encode