File constructor Null safety

1. Flutter
2. file
3. File
4. File constructor

File class

1. Constructors
2. File
3. Properties
4. absolute
5. basename
6. dirname
7. fileSystem
8. hashCode
9. isAbsolute
10. parent
11. path
12. runtimeType
13. uri
14. Methods
15. copy
16. copySync
17. create
18. createSync
19. delete
20. deleteSync
21. exists
22. existsSync
23. lastAccessed
24. lastAccessedSync
25. lastModified
26. lastModifiedSync
27. length
28. lengthSync
29. noSuchMethod
30. open
31. openRead
32. openSync
33. openWrite
34. readAsBytes
35. readAsBytesSync
36. readAsLines
37. readAsLinesSync
38. readAsString
39. readAsStringSync
40. rename
41. renameSync
42. resolveSymbolicLinks
43. resolveSymbolicLinksSync
44. setLastAccessed
45. setLastAccessedSync
46. setLastModified
47. setLastModifiedSync
48. stat
49. statSync
50. toString
51. watch
52. writeAsBytes
53. writeAsBytesSync
54. writeAsString
55. writeAsStringSync
56. Operators
57. operator ==