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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 get_current_release(self):
 """Get the release ID of the "current" deployment, None if there is no current deployment. This method performs one network operation. :return: Get the current release ID :rtype: str """

        current = self._runner.run("readlink '{0}'".format(self._current))
        if current.failed:
            return None
        return os.path.basename(current.strip())