def test_mixture(self):
		self.assertEqual(mn.max_negative([-20,5,10,-2,-1,10,0]),-1, msg="\
			should return -1")
	def test_all_negative(self):
		self.assertEqual(mn.max_negative([-20,-10,5,-50,-3]),-3, msg="\
			should return -3")
	def test_all_positive(self):
		self.assertEqual(mn.max_negative([20,10,10,5,2,1,10]),None, msg="\
			should return -1")
    def test_all_negative(self):
        self.assertEqual(mn.max_negative([-20, -10, 5, -50, -3]),
                         -3,
                         msg="\
			should return -3")
    def test_all_positive(self):
        self.assertEqual(mn.max_negative([20, 10, 10, 5, 2, 1, 10]),
                         None,
                         msg="\
			should return -1")
    def test_mixture(self):
        self.assertEqual(mn.max_negative([-20, 5, 10, -2, -1, 10, 0]),
                         -1,
                         msg="\
			should return -1")