human
I wrote the below code

    class MyConfigOptionParser(virtualenv.ConfigOptionParser, ):
        def __init__(self, *args, **kwargs):
            self.config = virtualenv.ConfigParser.RawConfigParser()
            self.files = []
            optparse.OptionParser.__init__(self, *args, **kwargs)
        def get_environ_vars(self, prefix='VIRTUALENV_'):
            (yield ('no_site_packages', '1'))
    cop = MyConfigOptionParser()
    cop.add_option('--no-site-packages', dest='system_site_packages', action='store_false', help="Don't    give    access    to    the    global    site-packages    dir    to    the    virtual    environment    (default)")
    defaults = {}
    cop.update_defaults(defaults)
    assert (defaults == {'system_site_packages': 0})

What's a good function header?

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

def test_cop_update_defaults_with_store_false():