Async locals are very misunderstood and the bane of my existence (though sometimes I also love them). TL;DR they are like "thread locals" but for asynchronous code. Modifications to async locals do *not* bleed outside of async methods. Below prints 11 then 10. #dotnet #dotnetcore 
If you remove the async and it will print 11 11. This is super important to understand if you're using async locals to flow context around in your application.
