OperationsExt constructor Null safety

1. spine_client
2. operations.pb
3. OperationsExt
4. OperationsExt constructor

OperationsExt class

1. Constructors
2. OperationsExt
3. Properties
4. hashCode
5. runtimeType
6. Methods
7. noSuchMethod
8. toString
9. Operators
10. operator ==
11. Static properties
12. operationInfo
13. Static methods
14. registerAllExtensions