Previously I posted PEP 560 two weeks ago, while several other PEPs were also posted, so it didn't get much of attention. Here I post the PEP 560 again, now including the full text for convenience of commenting.

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After creating the class,
the original bases are saved in ``__orig_bases__`` (currently this is also
done by the metaclass).

NOTE: These two method names are reserved for exclusive use by
the ``typing`` module and the generic types machinery, and any other use is
strongly discouraged.

The reference implementation (with tests) can be found
in [4]_, the proposal was originally posted and discussed on
the ``typing`` tracker, see [5]_.


Backwards compatibility and impact on users who don't use ``typing``:
=====================================================================

This proposal may break code that currently uses the names
``__class_getitem__`` and ``__subclass_base__``.

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