Creates an unordered identity-based set.
Effectively a shorthand for:
new HashSet<E>(equals: identical, hashCode: identityHashCode)
external factory HashSet.identity();
© 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/HashSet/HashSet.identity.html