How to use the cbapi.example_helpers.eprint function in cbapi

def subscribe_watchlist(cb, parser, args):
    try:
        cb.select(Feed, args.feed_id)
    except ObjectNotFoundError:
        eprint("Nonexistent or private feed: {}".format(args.feed_id))
        sys.exit(1)

    classifier = {
        "key": "feed_id",
        "value": args.feed_id,
    }

    watchlist_dict = {
        "name": args.watchlist_name,
        "description": args.description,
        "tags_enabled": args.tags,
        "alerts_enabled": args.alerts,
        "create_timestamp": args.timestamp,
        "last_update_timestamp": args.last_update,
        "report_ids": [],
        "classifier": classifier,

def get_report(watchlist, report_id=None, report_name=None):
    if report_id:
        reports = [report for report in watchlist.reports if report.id == report_id]
    elif report_name:
        reports = [report for report in watchlist.reports if report.title == report_name]
    else:
        raise ValueError("expected either report_id or report_name")

    if not reports:
        eprint("No matching reports found.")
        sys.exit(1)
    if len(reports) > 1:
        eprint("More than one matching report found.")
        sys.exit(1)

    return reports[0]

def replace_report(cb, parser, args):
    feed = get_feed(cb, feed_id=args.id, feed_name=args.feedname)

    imported = json.loads(sys.stdin.read())

    reports = feed.reports
    existing_report = next(
        (report for report in reports if imported["id"] == report.id), None
    )

    if existing_report:
        existing_report.update(**imported)
    else:
        eprint("No existing report to replace")
        sys.exit(1)

def get_report(feed, report_id=None, report_name=None):
    if report_id:
        reports = [report for report in feed.reports if report.id == report_id]

        if not reports:
            eprint("No reports with ID '{}'".format(report_id))
            sys.exit(1)
        elif len(reports) > 1:
            eprint("More than one report with ID '{}'".format(report_id))
            sys.exit(1)
    elif report_name:
        reports = [report for report in feed.reports if report.title == report_name]

        if not reports:
            eprint("No reports named '{}'".format(report_name))
            sys.exit(1)
        elif len(reports) > 1:
            eprint("More than one report named '{}'".format(report_name))
            sys.exit(1)
    else:
        raise ValueError("expected either report_id or report_name")

    return reports[0]

def get_report(watchlist, report_id=None, report_name=None):
    if report_id:
        reports = [report for report in watchlist.reports if report.id == report_id]
    elif report_name:
        reports = [report for report in watchlist.reports if report.title == report_name]
    else:
        raise ValueError("expected either report_id or report_name")

    if not reports:
        eprint("No matching reports found.")
        sys.exit(1)
    if len(reports) > 1:
        eprint("More than one matching report found.")
        sys.exit(1)

    return reports[0]

def import_report(cb, parser, args):
    feed = get_feed(cb, feed_id=args.id, feed_name=args.feedname)

    imp_dict = json.loads(sys.stdin.read())

    reports = feed.reports
    existing_report = next(
        (report for report in reports if imp_dict["id"] == report.id), None
    )

    if existing_report:
        eprint("Report already exists; use replace-report.")
        sys.exit(1)
    else:
        imp_report = cb.create(Report, imp_dict)
        feed.append_reports([imp_report])