get method

Implementation

Future<V> get(K key, {Loader<K, V> ifAbsent}) async {
  if (_map.containsKey(key)) {
    return _map[key];
  }
  // If this key is already loading then return the existing future.
  if (_outstanding.containsKey(key)) {
    return _outstanding[key];
  }
  if (ifAbsent != null) {
    var futureOr = ifAbsent(key);
    _outstanding[key] = futureOr;
    var v = await futureOr;
    _map[key] = v;
    _outstanding.remove(key);
    return v;
  }
  return null;
}