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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 _update_pbar(self, pbar_num=1, pbar_msg=None):
 """Update self._pbar and error message during pipeline evaluation. Parameters pbar_num: int How many pipelines has been processed pbar_msg: None or string Error message Returns ------- None """

        if not isinstance(self._pbar, type(None)):
            if self.verbosity > 2 and pbar_msg is not None:
                self._pbar.write(pbar_msg, file=self._file)
            if not self._pbar.disable:
                self._pbar.update(pbar_num)