def __init__(self, key=None, **kwargs):
    if not key:
      raise ValueError(u'Missing key.')

    super(RC4Decrypter, self).__init__()
    self._rc4_cipher = ARC4.new(key)
Initializes the decrypter object.
dataset/ETHPy150Open log2timeline/dfvfs/dfvfs/encryption/rc4_decrypter.py/RC4Decrypter.__init__