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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def normalize_lons(l1, l2):
 """ An international date line safe way of returning a range of longitudes. [(20, 30)] [(-17, 17)] [(-180, -178), (179, 180)] [(-180, -179), (178, 180)] [(-180, -179), (179, 180)] [(-180, -176), (177, 180)] """

    if l1 > l2:  # exchange lons
        l1, l2 = l2, l1
    delta = l2 - l1
    if l1 < 0 and l2 > 0 and delta > 180:
        return [(-180, l1), (l2, 180)]
    elif l1 > 0 and l2 > 180 and delta < 180:
        return [(l1, 180), (-180, l2 - 360)]
    elif l1 < -180 and l2 < 0 and delta < 180:
        return [(l1 + 360, 180), (l2, -180)]
    return [(l1, l2)]