def load_tse_bi(token_path):
    """Reads .tse_bi file and returns backgroud and seizure intervals

    Args:
        token_path: path to token file
            e.g. tuh_eeg/v1.0.0/edf/00000037/00001234/s001_2012_03_06
            /00001234_s001_t000

    Returns:
        tuple: intvs - list of intervals.   labels - list of labels.

    """
    intvs, labels = [], []
    with open(token_path+'.tse_bi', 'r') as fp:
        for line in fp:
            line = line.replace('\n', '').split(' ')
            if line[0] == 'version':
                if line[2] != 'tse_v1.0.0':
                    print("tse_bi file must be version='tse_v1.0.0'")
                    exit(-1)
                else:
                    continue
            elif line[0] is not '':
                intvs.append([float(line[0]), float(line[1])])
                labels.append(line[2])
            else:
                continue
    return intvs, labels