'Helper tests that assert basic sanity about the g4 tiff reading'

def _assert_noerr(self, im):

    self.assertEqual(im.mode, '1')
    im.load()
    im.getdata()
    try:
        self.assertEqual(im._compression, 'group4')
    except:
        print('No    _compression')
        print(dir(im))
    out = self.tempfile('temp.png')
    im.save(out)
    out_bytes = io.BytesIO()
    im.save(out_bytes, format='tiff', compression='group4')
