Unable to locate xg_helpers.py

[jgriffi]

xg_helpers library mentioned/referenced in book but I can't locate it in repo nor book.

[akthe-at]

@jgriffi This is a custom file you create and put the defined functions/classes into that @mattharrison highlights in the book. You then import this into your working file when building your memory. This keeps all of your function/class definitions out of your working space to keep it clean, and you can reuse them later if you turn them into a proper package/module.