SpeechPackageController constructor Null safety

1. irte_engine
2. speech_package_controller
3. SpeechPackageController
4. SpeechPackageController constructor

SpeechPackageController class

1. Constructors
2. SpeechPackageController
3. Properties
4. activeConditions
5. activePackage
6. activePackageStatus
7. hashCode
8. hasListeners
9. initialized
10. isClosed
11. listeners
12. onDelete
13. onStart
14. packages
15. runtimeType
16. Methods
17. $configureLifeCycle
18. activate
19. addListener
20. addListenerId
21. checkActive
22. dispose
23. disposeId
24. download
25. downloadAndActivate
26. extract
27. getPackForSettings
28. loadPackages
29. noSuchMethod
30. notifyChildrens
31. onClose
32. onInit
33. onReady
34. refresh
35. refreshGroup
36. removeListener
37. removeListenerId
38. setupActivePack
39. toString
40. update
41. Operators
42. operator ==
43. Static properties
44. instance