merge: check argument value with if/raise instead of an assert
This shouldn't make any difference for legal code, but it'll prevent
the assertion from being optimized out if someone decides to do -O on
our code.
Differential Revision: https://phab.mercurial-scm.org/D6879
from __future__ import absolute_import
import pkgutil
__path__ = pkgutil.extend_path(__path__, __name__)