def _get_meg_system(info):
    """Educated guess for the helmet type based on channels"""
    system = '306m'
    for ch in info['chs']:
        if ch['kind'] == FIFF.FIFFV_MEG_CH:
            coil_type = ch['coil_type'] & 0xFFFF
            if coil_type == FIFF.FIFFV_COIL_NM_122:
                system = '122m'
                break
            elif coil_type // 1000 == 3:  # All Vectorview coils are 30xx
                system = '306m'
                break
            elif (coil_type == FIFF.FIFFV_COIL_MAGNES_MAG or
                  coil_type == FIFF.FIFFV_COIL_MAGNES_GRAD):
                nmag = np.sum([c['kind'] == FIFF.FIFFV_MEG_CH
                               for c in info['chs']])
                system = 'Magnes_3600wh' if 150 > nmag else 'Magnes_2500wh'
                break
            elif coil_type == FIFF.FIFFV_COIL_CTF_GRAD:
                system = 'CTF_275'
                break
            elif coil_type == FIFF.FIFFV_COIL_KIT_GRAD:
                system = 'KIT'
                break
            elif coil_type == FIFF.FIFFV_COIL_BABY_GRAD:
                system = 'BabySQUID'
                break
    return system
dataset/ETHPy150Open mne-tools/mne-python/mne/channels/channels.py/_get_meg_system/swapped operands of `>`