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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 _all_minions(self, expr=None):
        '''
        Return a list of all minions that have auth'd
        '''
        mlist = []
        for fn_ in salt.utils.data.sorted_ignorecase(os.listdir(os.path.join(self.opts['pki_dir'], self.acc))):
            if not fn_.startswith('.') and os.path.isfile(os.path.join(self.opts['pki_dir'], self.acc, fn_)):
                mlist.append(fn_)
        return {'minions': mlist, 'missing': []}