def test_minimal(self):
        """
        For an empty beacon information object, the number of used
        beacons is zero, the number of seen beacons is zero, and the
        repr of the object reflects that.
        """
        bi = base.BeaconInformation()
        self.assertEqual(len(bi.usedBeacons), 0)
        expectedRepr = ("<BeaconInformation ("
                        "used beacons (0): [], "
                        "unused beacons: [])>")
        self.assertEqual(repr(bi), expectedRepr)

        For an empty beacon information object, the number of used
        beacons is zero, the number of seen beacons is zero, and the
        repr of the object reflects that.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/positioning/test/test_base.py