Motivation:
With reference counting it can be difficult to keep track of ownership and references.
When bugs arise in this area, it's good to get help from some tooling.
Modification:
Add a LifecycleTracer which records lifecycle changes.
This information can be attached to any lifecycle/ownership exceptions as suppressed exceptions.
The tracing is off by default, unless assertions are enabled.
Result:
It's now easier to debug reference counting/lifecycle/ownership issues.
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