def test_wh_under_zero(self):
"""test for wh_under_zero method
"""
r = Rectangle(1, 1)
# check that input must be >= 0 for width and height
with self.assertRaises(ValueError):
r.wh_under_zero(0, "width")
with self.assertRaises(ValueError):
r.wh_under_zero(-1, "width")
with self.assertRaises(ValueError):
r.wh_under_zero(0, "height")
with self.assertRaises(ValueError):
r.wh_under_zero(-1, "height")
