Operations constructor Null safety

1. jrpn
2. controller.operations
3. Operations
4. Operations constructor

Operations class

1. Constructors
2. Operations
3. Properties
4. hashCode
5. runtimeType
6. Methods
7. noSuchMethod
8. toString
9. Operators
10. operator ==
11. Static properties
12. abs
13. bsp
14. bst
15. chs
16. clearPrefix
17. clearPrgm
18. clearReg
19. clx
20. dot
21. eex
22. enter
23. fShift
24. gShift
25. lstx
26. mem
27. n0
28. n1
29. n2
30. n3
31. n4
32. n5
33. n6
34. n7
35. n8
36. n9
37. onOff
38. pr
39. pse
40. rDown
41. rs
42. rtn
43. rUp
44. special
45. sqrtOp
46. sst
47. status
48. xEQ0
49. xEQy
50. xGT0
51. xGTy
52. xLEy
53. xLT0
54. xNE0
55. xNEy
56. xSwapParenI
57. xy