def test_switch_average_A(self):
     self.assertEqual(switch_average('A'), 'a')
 def test_switch_average_B(self):
     self.assertEqual(switch_average('B'), 'b')
 def test_switch_average_F(self):
     self.assertEqual(switch_average('F'), -1)
 def test_switch_average_E(self):
     self.assertEqual(switch_average('E'), 'e')
 def test_switch_average_D(self):
     self.assertEqual(switch_average('D'), 'd')
 def test_switch_average_C(self):
     self.assertEqual(switch_average('C'), 'c')
 def test_B_return(self):
     self.assertEqual(assign_average.switch_average({'A': 1, 'B': 2, 'C': 3, 'D': 4, 'E': 5, 'a': 0.5, 'b': 0.25},
                                                    'B'), 'C')