def test_polar_coordinate_3(self):
a = Point(0, 0)
b = a.polar(-1, 0)
c = Point(-1, 0)
self.assertEqual(b, c)
def test_polar_coordinate_4(self):
a = Point(1, 1)
b = a.polar(1, math.pi / 2)
c = Point(1, 2)
self.assertEqual(b, c)
def test_polar_coordinate_2(self):
a = Point(0, 0)
b = a.polar(0, 0)
self.assertEqual(a, b)