addAll abstract method Null safety
- Iterable<
E> elements
Adds all elements to this set.
Equivalent to adding each element in elements using add,
but some collections may be able to optimize it.
final characters = <String>{'A', 'B'};
characters.addAll({'A', 'B', 'C'});
print(characters); // {A, B, C}
Implementation
void addAll(Iterable<E> elements);