Field_behavior constructor Null safety

1. spine_client
2. field_behavior.pb
3. Field_behavior
4. Field_behavior constructor

Field_behavior class

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