def usage(self, msg):
        self.stderr.write("Error: %s\n" % str(msg))
        self.stderr.write("For help, use %s -h\n" % self.progname)
        self.exit(2)
test the somewhat unusual case of [ticket:3341]
dataset/ETHPy150Open XiaoMi/minos/supervisor/supervisor/options.py/Options.usage--crossover with--dataset/ETHPy150Open zzzeek/sqlalchemy/test/ext/declarative/test_inheritance.py/DeclarativeInheritanceTest.test_single_constraint_on_sub