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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 do(self):
        'Do or redo the action'
        self._runner = self._generator(*self.args, **self.kwargs)
        rets = next(self._runner)
        if isinstance(rets, tuple):
            self._text = rets[0]
            return rets[1:]
        elif rets is None:
            self._text = ''
            return None
        else:
            self._text = rets
            return None