The keys of this.
The returned iterable has efficient length
and contains
operations, based on length and containsKey of the map.
The order of iteration is defined by the individual Map
implementation, but must be consistent between changes to the map.
Modifying the map while iterating the keys may break the iteration.
Iterable<K> get keys;
© 2012 the Dart project authors
Licensed under the Creative Commons Attribution-ShareAlike License v4.0.
https://api.dartlang.org/stable/2.0.0/dart-collection/MapMixin/keys.html