require function
message should be null
, String
or String Function()
Implementation
void require(final bool value, [final dynamic message]) {
if (!value) {
String? m;
if (message is String?) {
m = message;
} else if (message is String Function()) {
m = message();
} else {
throw InternalSealedError('message type is invalid');
}
throw SealedError(m);
}
}