def __init__(self, key):
if len(key) != <NUM_LIT:8>:<EOL><INDENT>raise ValueError("<STR_LIT>")<EOL><DEDENT>self.key = key<EOL>self._subkeys = self._create_subkeys(self.key)<EOL>
Creates a DES cipher class with the key initialised. This key must be
8 bytes in length. This only supports the ECB cipher mode as that is
what is used in the LM hash calculation.

:param key: The 8-byte key to use in the Cipher