def METHOD_NAME(self):
    # default cipher is AES-XTS with 512b key
    fmt = LUKS()
    self.assertEqual(fmt.cipher, "aes-xts-plain64")
    self.assertEqual(fmt.key_size, 512)
    # setting cipher shouldn't change the key size
    fmt = LUKS(cipher="aes-xts-plain64")
    self.assertEqual(fmt.key_size, 512)
    # all XTS mode ciphers should default to 512
    fmt = LUKS(cipher="serpent-xts-plain64")
    self.assertEqual(fmt.key_size, 512)
    # no default for non-XTS modes
    fmt = LUKS(cipher="aes-cbc-plain64")
    self.assertEqual(fmt.key_size, 0)