dart:collection

addAll method

void addAll(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.

Source

void addAll(Iterable<E> elements) {
  for (E element in elements) {
    int compare = _splay(element);
    if (compare != 0) {
      _addNewRoot(new _SplayTreeNode(element), compare);
    }
  }
}