hasLowercase<E> static method
Validates that the string contains at least one lowercase letter.
StringRules.hasLowercase(error: 'Must contain lowercase letter')
Implementation
static Rule<String, E> hasLowercase<E>({required E error}) => PredicateRule(
predicate: (value) => value.contains(RegExp(r'[a-z]')),
error: error,
);