'Do not raise on missing properties but backfill with empty values.'

def test_missing_property(self):

    wmi_raw_sampler = WMISampler('Win32_PerfRawData_PerfOS_System', ['UnknownCounter', 'MissingProperty'])
    wmi_raw_sampler.sample()
    self.assertWMISampler(wmi_raw_sampler, ['MissingProperty'], count=1)
