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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 _commonParent(zi1, zi2):
 """ Locate the common parent of two Interface objects. @param zi1: a zope Interface object. @param zi2: another Interface object. @return: the rightmost common parent of the two provided Interface objects, or None, if they have no common parent other than Interface itself. """

    shorter, longer = sorted([_linearize(x)[::-1] for x in zi1, zi2],
                             key=len)
    for n in range(len(shorter)):
        if shorter[n] != longer[n]:
            if n == 0:
                return None
            return shorter[n-1]
    return shorter[-1]