passes method
Validates the value using the given context.
Returns true if valid, otherwise false.
Implementation
@override
FutureOr<bool> passes(ValidationContext context) {
final value = context.value;
if (value == null) return false;
if (value is String) return value.trim().isNotEmpty;
if (value is Iterable) return value.isNotEmpty;
if (value is Map) return value.isNotEmpty;
return true;
}