def test_max_cell_all_zero(self):
     """Handle when the max value of any of the cells is zero"""
     grid = [
         [1, 5, 4],
         [3, 5, 6],
         [0, 0, 0],
         ]
     cells = [(0,0), (1,0), (2,0)]
     expected = (2,0)
     actual = max_cell(grid, cells)
     self.assertEqual(expected, actual)
 def test_max_cell(self):
     grid = [
         [1, 2, 4],
         [3, 5, 6],
         [7, 8, 9],
         ]
     cells = [(0,0), (1,0), (2,0)]
     expected = (2,0)
     self.assertEqual(9, value_at(grid, expected))
     actual = max_cell(grid, cells)
     self.assertEqual(expected, actual)