splitTime property Null safety

1. irte_engine
2. split_time_pipeline
3. SplitTimePipeline
4. splitTime property

SplitTimePipeline class

1. Constructors
2. SplitTimePipeline
3. Properties
4. connections
5. end
6. hashCode
7. hasListeners
8. initialized
9. isClosed
10. json
11. lastSplitTime
12. listeners
13. name
14. onDelete
15. onStart
16. processes
17. registry
18. result
19. rules
20. runtimeType
21. splitTime
22. start
23. Methods
24. $configureLifeCycle
25. addListener
26. addListenerId
27. dispose
28. disposeId
29. filterSplitTimeResult
30. metersForSplitTime
31. noSuchMethod
32. notifyChildrens
33. onClose
34. onInit
35. onReady
36. processItem
37. propagateSplitTime
38. refresh
39. refreshGroup
40. removeListener
41. removeListenerId
42. toString
43. update
44. Operators
45. operator ==
46. Static properties
47. defaultRules