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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 unique_id(self):
 """ Determine a "unique id" for this repository Returns: str: Repository UUID of this repository """

        cmd = 'svn info | grep "^Repository UUID"'
        cmdo = self.sh(cmd,
                       shell=True,
                       ignore_error=True)
        if cmdo:
            return cmdo.split(': ', 1)[1].rstrip()
        return None