'See the docs for xmodule.modulestore.mixed.MixedModuleStore'

def update_item(self, xblock, user_id, allow_not_found=False, **kwargs):

    with remove_ccx(xblock) as (xblock, restore):
        return restore(self._modulestore.update_item(xblock, user_id, allow_not_found=allow_not_found, **kwargs))
