def pop(self, key, *args):
            'Remove *key* from maps[0] and return its value. Raise KeyError if *key* not in maps[0].'
            try:
                return self.maps[0].pop(key, *args)
            except KeyError:
                raise KeyError('Key not found in the first mapping: {!r}'.format(key))
Remove *key* from maps[0] and return its value. Raise KeyError if *key* not in maps[0].
product/gradle-plugin/src/main/python/pip/_vendor/distlib/compat.py