The generation this isolate may serve against, or undefined when it does not know one.
Undefined past GENERATION_TRUST_MS, which bounds staleness: the request falls through to
the object, whose response teaches this isolate the current generation again.
The generation this isolate may serve against, or undefined when it does not know one.
Undefined past GENERATION_TRUST_MS, which bounds staleness: the request falls through to the object, whose response teaches this isolate the current generation again.