test: 💍 fix default value for headers
if None, create a new dict. Previous situation was that the default
dictionary was created at function creation, then mutated on every call.
Also: add traceback to exception raising. (all are suggestions by
sourcery.ai in vscode)
test: 💍 fix default value for headers: if None, create a new dict. Previous situation was that the default
dictionary was created at function creation, then mutated on every call.
Also: add traceback to exception raising. (all are suggestions by
sourcery.ai in vscode)