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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 commands(self):
 """Get all commands of the benchmark category :return generator of string """

        for child in self._children:
            with open(osp.join(child, YAML_REPORT_FILE)) as istr:
                command = yaml.safe_load(istr)['command']
                yield ' '.join(map(six.moves.shlex_quote, command))