def tearDown(self):
    try:
        super(TT, self).tearDown()
    finally:
        for (k, v) in self.env.items():
            del os.environ[k]
def tearDown(self):
    try:
        super(TT, self).tearDown()
    finally:
        for (k, v) in self.env.items():
            del os.environ[k]