$os property non-nullable

[ambitionphp]

My project started receiving an uptick in Bugsnag errors: Undefined property: WhichBrowser\Model\Os::$version

My solution was to change $result->os->version?->value to $result->os?->version?->value, however, that caused static analysis errors due to $os being non-nullable.

I was forced to temporarily create a stub file which marks the $os property as being nullable to resolve the issue.