Stream<T> constructor Null safety

1. Flutter
2. dart:async
3. Stream<T>
4. Stream constructor

Stream class

1. Constructors
2. Stream
3. empty
4. error
5. eventTransformed
6. fromFuture
7. fromFutures
8. fromIterable
9. multi
10. periodic
11. value
12. Properties
13. first
14. hashCode
15. isBroadcast
16. isEmpty
17. last
18. length
19. runtimeType
20. single
21. Methods
22. any
23. asBroadcastStream
24. asyncExpand
25. asyncMap
26. cast
27. contains
28. distinct
29. drain
30. elementAt
31. every
32. expand
33. firstWhere
34. fold
35. forEach
36. handleError
37. join
38. lastWhere
39. listen
40. map
41. noSuchMethod
42. pipe
43. reduce
44. singleWhere
45. skip
46. skipWhile
47. take
48. takeWhile
49. timeout
50. toList
51. toSet
52. toString
53. transform
54. where
55. Operators
56. operator ==
57. Static methods
58. castFrom