if "sbd_interest_rate" in kwargs:
                super(WitnessProps, self).__init__(OrderedDict([
                    ('account_creation_fee', Amount(kwargs["account_creation_fee"], prefix=prefix)),
                    ('maximum_block_size', Uint32(kwargs["maximum_block_size"])),
                    ('sbd_interest_rate', Uint16(kwargs["sbd_interest_rate"])),