Parameters
    ----------
    dipole_mode: Which dipoles should be extracted
        "all"
        "before"
        "between"
        "after"

def _parse_radic_header(header_group, dipole_mode="all"):
    """
    Parameters
    ----------
    dipole_mode: Which dipoles should be extracted
        "all"
        "before"
        "between"
        "after"
    """
    header = ''.join(header_group[1])

    nr_of_electrodes = _get_nr_of_electrodes(header.split('\n'))
    groups = itertools.groupby(
        header.split('\n'),
        lambda line: (
            line.startswith('[End Readings]') or
            line.startswith('[Begin Readings]')
        )
    )

    for key, group in groups:
        # there is only one group we are interested in: the first one
        if key:
            tmp = np.array(
                [
                    np.fromstring(
                        x, sep=' ', dtype=int
                    )
                    for x in next(groups)[1]
                ],
            )

            # curpots = tmp.T.copy()
            # curpots.resize(nr_of_electrodes + 2, tmp.shape[0])
            break

    # now we have the raw readings, pad them with zeros
    readings = []
    for raw_reading in tmp:
        voltage_rus = raw_reading[3:]
        # note that we now have the last electrode in here, too (so one more
        # than we have RUs. This electrode is always 0
        normed_reading = np.zeros(nr_of_electrodes)
        for i in voltage_rus[np.where(voltage_rus > 0)]:
            normed_reading[i - 1] = i
        readings.append(np.hstack((raw_reading[0:3], normed_reading)))

    # now generate the available configurations
    # add calibration
    reading_configs = {}
    for nr, reading in enumerate(readings):
        # nr = reading[0]
        A = reading[1]
        B = reading[2]

        voltages = []

        # loop over the RU-settings
        # we always measure to the next zero electrode
        for i in range(3, nr_of_electrodes + 3):
            for j in range(i + 1, nr_of_electrodes + 3):
                if reading[j] == 0:
                    M = i - 2
                    N = j - 2
                    all_active = ((reading[i] == 0) and (reading[j] == 0))
                    # print('a', 'b', 'm, n', A, B, M, N, all_active)
                    voltages.append((A, B, M, N, all_active))
                    break

        reading_configs[nr + 1] = np.array(voltages)
    return reading_configs