typing: fix a syntax error in mercurial/cext/bdiff.pyi
I noticed because `merge-pyi` on the non-cext implementations with this file as
input skipped the return type for this. `pytype-single --parse-pyi` confirmed
it was a problem.
# Dummy extension that adds a delay after acquiring a lock.
#
# This extension can be used to test race conditions between lock acquisition.
import os
import time
def reposetup(ui, repo):
class delayedlockrepo(repo.__class__):
def lock(self, wait=True):
delay = float(os.environ.get('HGPRELOCKDELAY', '0.0'))
if delay:
time.sleep(delay)
res = super(delayedlockrepo, self).lock(wait=wait)
delay = float(os.environ.get('HGPOSTLOCKDELAY', '0.0'))
if delay:
time.sleep(delay)
return res
repo.__class__ = delayedlockrepo