def test_concistency(self):
    for row in range(1, 12):
        for col in range(1, 12):
            ref = _rc2ref(row, col)
            (r, c) = _ref2rc(ref)
            self.assertEqual((r, c), (row, col), f'({row},{col}) -> {ref} -> ({r}, {c}) != ({row},{col})')
def test_concistency(self):
    for row in range(1, 12):
        for col in range(1, 12):
            ref = _rc2ref(row, col)
            (r, c) = _ref2rc(ref)
            self.assertEqual((r, c), (row, col), f'({row},{col}) -> {ref} -> ({r}, {c}) != ({row},{col})')