mutateInPlace
Mutate this container in place. MUST ONLY be done by a scope that owns this container for its current render pass (tracked by ComponentScope.ownedStateContainer); the caller guarantees that with an identity check.
Mutate this container in place. MUST ONLY be done by a scope that owns this container for its current render pass (tracked by ComponentScope.ownedStateContainer); the caller guarantees that with an identity check.