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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 shorten(self, tag):
 """ Get the short representation of a fully qualified tag :param str tag: a (fully qualified or not) XML tag """

        if tag.startswith('{'):
            ns, _tag = tag.rsplit('}')
            tag = self.nsmap.get(ns[1:], '') + _tag
        return tag