##### Set class

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

# retainWhere method

void retainWhere (bool test(E element))

Removes all elements of this set that fail to satisfy `test`.

## Implementation

    void retainWhere(bool test(E element));