human
Complete this python program:
def addTZCleanup(testCase):
assistant
#Here is the Python code you requested.

    """Add cleanup hooks to a test case to reset timezone to original value.
    @param testCase: the test case to add the cleanup to.
    @type testCase: L{unittest.TestCase}
    """
    tzIn = environ.get('TZ', None)
    @testCase.addCleanup
    def resetTZ():
        setTZ(tzIn)