julia

1574aa0f - Make usage of `foo` clearer (#22317)

Make usage of `foo` clearer (#22317) Replaces the placeholder `foo` with the built-in `norm` to make sure the example works when typed into a julia program. Thanks to Avik Sengupta for the text and for all the commenters on https://discourse.julialang.org/t/what-does-foo-in-the-parallel-computing-docs-refer-to/4182 for making this happen.