def conversion_base_line_helper(data, period):
    """
    The only real difference between TenkanSen and KijunSen is the period value
    """
    catch_errors.check_for_period_error(data, period)
    cblh = [(np.max(data[idx+1-period:idx+1]) +
            np.min(data[idx+1-period:idx+1])) / 2 for idx in range(period-1, len(data))]

    cblh = fill_for_noncomputable_vals(data, cblh)
    return cblh
The only real difference between TenkanSen and KijunSen is the period value