Upper Band.

    Formula:
    UB = CB + BW

def upper_band(close_data, high_data, low_data, period):
    """
    Upper Band.

    Formula:
    UB = CB + BW
    """
    cb = center_band(close_data, high_data, low_data, period)
    bw = band_width(high_data, low_data, period)
    ub = cb + bw
    return ub