def __init__(self, ciphertext: bytes, blocksize: int=16):
    if (not isinstance(ciphertext, bytes)):
        raise Exception(f'Ciphertext {type(ciphertext)} not an instance of {bytes}')
    self.ciphertext = ciphertext
    self.blocksize = blocksize
def __init__(self, ciphertext: bytes, blocksize: int=16):
    if (not isinstance(ciphertext, bytes)):
        raise Exception(f'Ciphertext {type(ciphertext)} not an instance of {bytes}')
    self.ciphertext = ciphertext
    self.blocksize = blocksize