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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 _run_progress_callbacks(self, bytes_transferred):
        ''' pass the number of bytes process to progress callbacks '''
        if bytes_transferred:
            for callback in self._progress_callbacks:
                try:
                    callback(bytes_transferred=bytes_transferred)
                except Exception as ex:
                    logger.error("Exception: %s" % str(ex))