def test_badVariationSign(self):
        """
        Setting a bogus sign value (not -1 or 1) on a coordinate raises
        C{ValueError} and doesn't affect the coordinate.
        """
        value = 50.0
        c = base.Coordinate(value, Angles.LATITUDE)

        self.assertRaises(ValueError, c.setSign, -50)
        self.assertEqual(c.inDecimalDegrees, 50.)

        self.assertRaises(ValueError, c.setSign, 0)
        self.assertEqual(c.inDecimalDegrees, 50.)

        self.assertRaises(ValueError, c.setSign, 50)
        self.assertEqual(c.inDecimalDegrees, 50.)

        Setting a bogus sign value (not -1 or 1) on a coordinate raises
        C{ValueError} and doesn't affect the coordinate.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/positioning/test/test_base.py