SetFinalizer is a wrapper around runtime.SetFinalizer that is a no-op under race builds or if neither the invariants or tracing build tags are specified.

Sometimes returns true percent% of the time if we were built with the "invariants" of "race" build tags.

Enabled is true if we were built with the "invariants" or "race" build tags.

RaceEnabled is true if we were built with the "race" build tag.

CloseChecker is used to check that objects are closed exactly once.

Value is a generic container for a value that should only exist in invariant builds.