A backport of recent additions to the 'collections.abc' module.
Currently, patch() provides the following names if missing:
All of them are also available directly from the backports_abc module namespace.
In Python 2.x and Python 3.2, it patches the collections module instead of the collections.abc module. Any names that are already available when importing this module will not be overwritten.
The names that were previously patched by patch() can be queried through the mapping in backports_abc.PATCHED.