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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 mangle_package_path(self, files):
 """Mangle paths for post-UsrMove systems. If the system implements UsrMove, all files will be in '/usr/[s]bin'. This method substitutes all the /[s]bin references in the 'files' list with '/usr/[s]bin'. :param files: the list of package managed files """

        paths = []

        def transform_path(path):
            # Some packages actually own paths in /bin: in this case,
            # duplicate the path as both the / and /usr version.
            skip_paths = ["/bin/rpm", "/bin/mailx"]
            if path in skip_paths:
                return (path, os.path.join("/usr", path[1:]))
            return (re.sub(r'(^)(/s?bin)', r'\1/usr\2', path),)

        if self.usrmove:
            for f in files:
                paths.extend(transform_path(f))
            return paths
        else:
            return files