def get_next_id(self):
        try:
            query = {'_id': 'last_id'}
            update = {'$inc': {'id': 1}}
            fn = self.db.internal.find_and_modify
            row = fn(query, update, upsert=True, new=True)
        except Exception as e:
            raise DatabaseException(e)
        return row['id']
def get_git_version(self):
        VERSION_PFX = 'git version '
        version = self.run_command(
            ['version'], show_stdout=False, stdout_only=True
        )
        if version.startswith(VERSION_PFX):
            version = version[len(VERSION_PFX):].split()[0]
        else:
            version = ''
        # get first 3 positions of the git version because
        # on windows it is x.y.z.windows.t, and this parses as
        # LegacyVersion which always smaller than a Version.
        version = '.'.join(version.split('.')[:3])
        return parse_version(version)