Display intermediate progress.

def _display(self, sent, now, chunk, mbps):
        """ Display intermediate progress. """
        if self.parent is not None:
            self.parent._display(self.parent.offset + sent, now, chunk, mbps)
            return

        elapsed = now - self.startTime

        if sent > 0 and self.total is not None and sent <= self.total:
            eta = (self.total - sent) * elapsed.total_seconds() / sent
            eta = datetime.timedelta(seconds=eta)
        else:
            eta = None

        self.output.write(
            "\r %s: Sent %s%s%s ETA: %s (%s) %s%20s\r" % (
                elapsed,
                util.humanize(sent),
                "" if self.total is None else " of %s" % (util.humanize(self.total),),
                "" if self.total is None else " (%d%%)" % (int(100 * sent / self.total),),
                eta,
                "" if not mbps else "%.3g Mbps " % (mbps,),
                chunk or "",
                " ",
            )
        )

        self.output.flush()