def test_get_byte_n_n_too_small_raises(self):
     with self.assertRaises(IndexError):
         get_byte_n(b'123', -4)
 def test_get_byte_n_n_too_large_raises(self):
     with self.assertRaises(IndexError):
         get_byte_n(b'123', 3)
    def test_get_byte_n_nominal_case(self):
        b = b'123'

        self.assertEqual(b'3', get_byte_n(b, 2))
    def test_get_byte_n_negative_indexing(self):
        b = b'123'

        self.assertEqual(b'3', get_byte_n(b, -1))
 def test_get_byte_n_empty_bytes_raises(self):
     with self.assertRaises(IndexError):
         get_byte_n(b'', 0)