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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 changed(self, filename='.md5', glob=None):
 """Are any of the files matched by ``glob`` changed? """

        if glob is not None:
            filename += '.glob-' + ''.join(ch.lower()
                                           for ch in glob if ch.isalpha())
        return changed(self, filename, glob=glob)