1. flutter_chips_input
2. dart:collection
3. SplayTreeMap<K, V>
4. firstKey method

##### SplayTreeMap class

1. Constructors
2. SplayTreeMap
3. from
4. fromIterable
5. fromIterables
6. of
7. Properties
8. isEmpty
9. isNotEmpty
10. keys
11. length
12. values
13. entries
14. hashCode
15. runtimeType
16. Methods
17. addAll
18. clear
19. containsKey
20. containsValue
21. firstKey
22. firstKeyAfter
23. forEach
24. lastKey
25. lastKeyBefore
26. putIfAbsent
27. remove
28. addEntries
29. cast
30. map
31. noSuchMethod
32. removeWhere
33. toString
34. update
35. updateAll
36. Operators
37. operator []
38. operator []=
39. operator ==

# firstKey method

K firstKey ()

Get the first key in the map. Returns `null` if the map is empty.

## Implementation

    K firstKey() {
      if (_root == null) return null;
      return _first.key;
    }