containsKeys function
Validator that checks if a map contains a specific set of keys.
Implementation
IValidator containsKeys(Iterable<String> keys, {String? message}) => _mapPredicateValidator(
message: message ?? 'contains keys: ${prettifyValue(keys)}',
test: (m) => !keys.any((key) => !m.containsKey(key)),
code: ExpectationCodes.valueContainsMissing,
);