DoubleLinkedQueue<E> constructor Null safety

1. Dart
2. dart:collection
3. DoubleLinkedQueue<E>
4. DoubleLinkedQueue constructor

DoubleLinkedQueue class

1. Constructors
2. DoubleLinkedQueue
3. from
4. of
5. Properties
6. first
7. hashCode
8. isEmpty
9. isNotEmpty
10. iterator
11. last
12. length
13. runtimeType
14. single
15. Methods
16. add
17. addAll
18. addFirst
19. addLast
20. any
21. cast
22. clear
23. contains
24. elementAt
25. every
26. expand
27. firstEntry
28. firstWhere
29. fold
30. followedBy
31. forEach
32. forEachEntry
33. join
34. lastEntry
35. lastWhere
36. map
37. noSuchMethod
38. reduce
39. remove
40. removeFirst
41. removeLast
42. removeWhere
43. retainWhere
44. singleWhere
45. skip
46. skipWhile
47. take
48. takeWhile
49. toList
50. toSet
51. toString
52. where
53. whereType
54. Operators
55. operator ==