Disable polyester threads if in an outer @batch loop

The readme gives this example, which works great:
```
disable_polyester_threads() do
@threads for i in 1:n
f()
end
end
```

For my use case, I would like to disable an inner `@batch` in `f()` if the outer loop uses `@batch`. Eg,:
```
disable_polyester_threads() do
@batch for i in 1:n
f()
end
end
```

Is there an easy way to do this? Thanks.