def test_remove_cell_5(self):
sb = SudokuBoard()
start_state = copy.deepcopy(sb.__dict__)
self.assertIsNone(sb.remove_cell("hello", 3))
self.assertDictEqual(sb.__dict__, start_state)
def test_remove_cell_1(self):
sb = SudokuBoard()
sb.set_cell(1, 2, 3)
start_state = copy.deepcopy(sb.__dict__)
self.assertEqual(sb.remove_cell(1, 2), 3)
self.assertDictEqual(sb.__dict__, {**start_state, "_cells": {}})
