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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 units_convertible(units1, units2, reftimeistime=True):
 """ Return True if a Unit representing the string units1 can be converted to a Unit representing the string units2, else False. :param str units1: A string representing the units :param str units2: A string representing the units """

    try:
        u1 = Unit(units1)
        u2 = Unit(units2)
    except ValueError:
        return False
    return u1.is_convertible(u2)