Bootstrap extension example

[isker]

Would be nice to have an example showing how to e.g. project shared state from a bootstrap extension into worker thread local variables, used by HTTP/etc extensions running in workers. I have bootstrap HTTP callouts as the source of this state in mind, but they aren't released in 1.37, I don't think?

[mathetake]

I think yeah the callout was not released in v1.37 but only on the main branch