latitude property Null safety

1. irte_engine
2. location_update
3. LocationUpdate
4. latitude property

LocationUpdate class

1. Constructors
2. LocationUpdate
3. fromLocationData
4. initial
5. Properties
6. accuracy
7. averageSpeed
8. hashCode
9. id
10. latitude
11. longitude
12. metersPassed
13. originalLocation
14. runtimeType
15. speed
16. timeElapsed
17. timestamp
18. Methods
19. noSuchMethod
20. toString
21. Operators
22. operator ==