importlib.abc.ResourceLoader, when in fact it did not. Fixed the ABC to inherit
as documented.
This doesn't introduce an backwards-incompatiblity as the code in PyLoader
already required the single method ResourceLoader defined as an abstract
method.
(mostly stuff specified by PEP 302). There are two ABCs, PyLoader and
PyPycLoader, which help with implementing source and source/bytecode loaders by
implementing load_module in terms of other methods. This removes a lot of
gritty details loaders typically have to worry about.
Brett Cannon