def test_writing_a_cell_should_not_modify_others(self):
grid = Grid()
grid.writeCell("hello",(0,0))
self.assertEqual("hello",grid.readCell((0,0)))
grid.writeCell("good bye",(0,0))
self.assertEqual("good bye",grid.readCell((0,0)))
grid.writeCell("In a new cell",(0,1))
self.assertEqual("good bye",grid.readCell((0,0)))
self.assertEqual("In a new cell",grid.readCell((0,1)))
def test_read_empty_cell_should_return_empty_string(self):
grid = Grid()
self.assertEqual("",grid.readCell((0,0)))
