textDomain function
Set the current default message catalog to domainName.
If domainName is null, return the current default.
If domainName is "", reset to the default of "messages".
Implementation
String? textDomain(String? domainName) {
final domain = domainName == null ? ffi.nullptr : domainName.toNativeUtf8();
final output = _func(domain);
if (output == ffi.nullptr) return null;
return output.toDartString();
}