addEntries method
As Map.addEntries.
Implementation
void addEntries(Iterable<MapEntry<K, V>> newEntries) {
  _safeMap.addEntries(newEntries);
}As Map.addEntries.
void addEntries(Iterable<MapEntry<K, V>> newEntries) {
  _safeMap.addEntries(newEntries);
}