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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 _check_minions_directories(self):
        '''
        Return the minion keys directory paths
        '''
        minions_accepted = os.path.join(self.opts['pki_dir'], self.ACC)
        minions_pre = os.path.join(self.opts['pki_dir'], self.PEND)
        minions_rejected = os.path.join(self.opts['pki_dir'],
                                        self.REJ)

        minions_denied = os.path.join(self.opts['pki_dir'],
                                        self.DEN)
        return minions_accepted, minions_pre, minions_rejected, minions_denied