addValues method
As SetMultimap.addValues.
Implementation
void addValues(K key, Iterable<V> values) {
  // _disown is called in add.
  values.forEach((value) {
    add(key, value);
  });
}As SetMultimap.addValues.
void addValues(K key, Iterable<V> values) {
  // _disown is called in add.
  values.forEach((value) {
    add(key, value);
  });
}