def unpack(msg):
    pid, length = struct.unpack("<HH", msg[:4])
    data = msg[4:4 + length]
    return pid, length, data
Install the predicates with reg.
dataset/ETHPy150Open braiden/python-ant-downloader/antd/garmin.py/unpack--crossover with--dataset/ETHPy150Open morepath/morepath/morepath/predicate.py/PredicateRegistry.install_predicates