getAll abstract method
Retrieves all key-value pairs from the storage.
This method fetches all stored key-value pairs and returns them as a map.
If an allowList is provided, only the key-value pairs whose keys are
present in the allow list will be included in the result.
Parameters:
allowList- Optional. An iterable of keys to filter the results. If provided, only key-value pairs with keys in this list will be returned. Ifnullor not provided, all key-value pairs are returned.
Returns a Future that completes with a map containing the requested key-value pairs. The map will be empty if no values exist or if none of the keys in the allow list are found.
Throws:
- ArgumentError if any key in the allow list is invalid.
Implementation
Future<Map<String, dynamic>> getAll(Set<String> allowList);