getAndRemove method

@override Future getAndRemove(String key)

Removes the entry for a key only if currently mapped to some value.

• key: key with which the specified value is associated

Returns the value if one existed or null if no mapping existed for this key

Implementation

@override
Future<dynamic> getAndRemove(String key) {
  return _primary.getAndRemove(key).then((value) {
    if (value == null) {
      return _secondary.getAndRemove(key);
    }

    return _secondary.remove(key).then((any) => value);
  });
}