<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _progress_update(self, numerator_increment, stage=0, show_eta=True, **kw):
 """ Updates the progress. Will update progress bars or other progress output. Parameters numerator : int numerator of partial work done already in current stage stage : int, nonnegative, default=0 Current stage of the algorithm, 0 or greater """

        if not self.show_progress:
            return

        self.__check_stage_registered(stage)

        if not self._prog_rep_progressbars[stage]:
            return

        pg = self._prog_rep_progressbars[stage]
        pg.update(int(numerator_increment))