QueryBase constructor Null safety

1. sendbird_sdk
2. base_query
3. QueryBase
4. QueryBase constructor

QueryBase class

1. Constructors
2. QueryBase
3. Properties
4. hashCode
5. hasNext
6. limit
7. loading
8. runtimeType
9. token
10. Methods
11. loadNext
12. noSuchMethod
13. toString
14. Operators
15. operator ==