human
I wrote the below code

    if is_platform_windows():
        import pytest
        pytest.skip('timezone    setting    not    supported    on    windows')
    import os
    import time
    def setTZ(tz):
        if (tz is None):
            try:
                del os.environ['TZ']
            except:
                pass
        else:
            os.environ['TZ'] = tz
            time.tzset()
    orig_tz = os.environ.get('TZ')
    setTZ(tz)
    try:
        (yield)
    finally:
        setTZ(orig_tz)

What's a good function header?
 ... Here's a good function header?
assistant
#Here's a good function header.

@contextmanager
def set_timezone(tz):