import funcsigs  
        with dag_maker():
            ret = f()
        ret.operator.run(start_date=DEFAULT_DATE, end_date=DEFAULT_DATE)
    def test_fail(self, dag_maker):
        @task.virtualenv()
        def f():
            raise Exception
        with dag_maker():
            ret = f()
        with pytest.raises(CalledProcessError):
            ret.operator.run(start_date=DEFAULT_DATE, end_date=DEFAULT_DATE)
    def test_python_3(self, dag_maker):
        @task.virtualenv(python_version=3, use_dill=False, requirements=["dill"])
        def f():
            import sys
            print(sys.version)
            try:
                {}.iteritems()
            except AttributeError:
                return
            raise Exception
        with dag_maker():
            ret = f()
        ret.operator.run(start_date=DEFAULT_DATE, end_date=DEFAULT_DATE)
    def test_with_args(self, dag_maker):