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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 _getUniqueDev(self, devpath):
 """Return unique device for any block device path. @param devpath: Full path for block device. @return: Unique device string without the /dev prefix. """

        realpath = os.path.realpath(devpath)
        mobj = re.match('\/dev\/(.*)$', realpath)
        if mobj:
            dev = mobj.group(1)
            if dev in self._diskStats:
                return dev
            else:
                try:
                    (major, minor) = self._getDevMajorMinor(realpath)
                except:
                    return None
                return self._mapMajorMinor2dev.get((major, minor))
        return None