exception method
Informs the report that an excetion happened w/in the framework itself. This is likely a non-recoverable error and should be investigated.
This will also end all pending steps and mark them as failed using the
given message
as the error.
Implementation
void exception(String message, dynamic e, StackTrace stack) {
final re = '$message: $e\n$stack';
_runtimeException = re;
_pendingSteps.forEach((step) => endStep(step));
_exceptionStreamController?.add(re);
}