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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 convert_units_to_base_units(units):
 """Convert a set of units into a set of "base" units. Returns a 2-tuple of `factor, new_units`. """

    total_factor = 1
    new_units = []
    for unit in units:
        if unit not in BASE_UNIT_CONVERSIONS:
            continue

        factor, new_unit = BASE_UNIT_CONVERSIONS[unit]
        total_factor *= factor
        new_units.append(new_unit)

    new_units.sort()
    return total_factor, tuple(new_units)