I just added solutions to the empty String challenge in the blog post. This includes a very interesting find from Xavier Cooney, that causes the same problem wi

I just added solutions to the empty String challenge in the blog post. This includes a very interesting find from Xavier Cooney, that causes the same problem without involving any concurrency. It instead makes StringBuilder misbehave by throwing an exception at an unexpected place: https://gist.github.com/XavierCooney/e9f6235f05479ac6bf962ca25e31d8d0 https://gist.github.com/XavierCooney/e9f6235f05479ac6bf962ca...