def test_variation(self):
        """
        The repr of an empty variation says that it is a variation of unknown
        value.
        """
        a = base.Angle(angleType=Angles.VARIATION)
        self.assertEqual("<Variation (unknown value)>", repr(a))

        The repr of an empty variation says that it is a variation of unknown
        value.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/positioning/test/test_base.py