def __init__(self, header, enc_payload=None):
        self.header = header
        self.enc_payload = enc_payload
Same args as unsubscribe_mailchimp, used to have the task be run asynchronously
dataset/ETHPy150Open nskinkel/oppy/oppy/cell/fixedlen.py/EncryptedCell.__init__--crossover with--dataset/ETHPy150Open CenterForOpenScience/osf.io/website/mailchimp_utils.py/unsubscribe_mailchimp_async