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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 _mutate(self):
        '''
        Mutate enclosed fields
        '''
        for i in range(self._field_idx, len(self._fields)):
            self._field_idx = i
            if self._current_field().mutate():
                return True
            self._current_field().reset()
        return False