computeIfAbsentAsync method

Future<V> computeIfAbsentAsync(K key, Future<V> ifAbsent(K key))

Implementation

Future<V> computeIfAbsentAsync(
    K key, Future<V> Function(K key) ifAbsent) async {
  if (!containsKey(key)) {
    this[key] = await ifAbsent(key);
  }
  return this[key]!;
}