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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 _print_throbber(self):
        '''Print an indefinite progress bar.'''
        self._print('[')

        for position in range(self._bar_width):
            self._print('O' if position == self._throbber_index else ' ')

        self._print(']')

        self._throbber_index = next(self._throbber_iter)