def decode_parameters(string):
    parameters = collect_parameters(string)
    groups = {}
    for k, parts in groupby(parameters, get_key):
        groups[k] = concatenate(list(parts))
    return groups
Parameters can be splitted into several parts, e.g.
dataset/ETHPy150Open mailgun/flanker/flanker/mime/message/headers/parametrized.py/decode_parameters