Typed property Firehed\JWT\JWT::$keys must not be accessed before initialization

[Firehed]

Typed property Firehed\JWT\JWT::$keys must not be accessed before initialization in /app/vendor/firehed/jwt/src/JWT.php:49

To reproduce:

$jwt = new JWT(['a' => 'b']);
echo $jwt->getEncoded();

While this goes against the usage of explicitly calling setKeys() per the documentation, IMO it's a flawed API design where you can enter this situation at all. Regrettably, fixing it all the way through ends up being a breaking change somewhere along the way, likely either in the JWT constructor or in the getEncoded method.