How to use the pyperf._cli.empty_line function in pyperf

lines.append("Number of benchmarks: %s" % len(suite))
                        lines.append("Total duration: %s" % format_seconds(duration))
                        dates = suite.get_dates()
                        if dates:
                            start, end = dates
                            lines.append("Start date: %s" % format_datetime(start, microsecond=False))
                            lines.append("End date: %s" % format_datetime(end, microsecond=False))

                if show_name:
                    format_title(item.name, 2, lines=lines)

                empty_line(lines)
                lines.extend(bench_lines)

            if lines:
                empty_line(output)
                output.extend(lines)

        for line in output:
            print(line)

        if not output and only_checks:
            if len(data) == 1:
                print("The benchmark seems to be stable")
            else:
                print("All benchmarks seem to be stable")
    else:
        for line in output:
            print(line)

        show_filename = (data.get_nsuite() > 1)

break

    if use_title:
        show_filename = (data.get_nsuite() > 1)
        show_name = not data.has_same_unique_benchmark()
        if not show_filename and stats:
            show_filename = (len(data) > 1)

        suite = None
        for index, item in enumerate(data):
            lines = []

            if show_metadata:
                metadata = metadatas[index]
                if metadata:
                    empty_line(lines)
                    lines.append("Metadata:")
                    format_metadata(metadata, lines=lines)

            bench_lines = format_benchmark(item.benchmark,
                                           hist=hist,
                                           stats=stats,
                                           dump=dump,
                                           checks=checks,
                                           result=result,
                                           display_runs_args=display_runs_args)

            if bench_lines:
                empty_line(lines)
                lines.extend(bench_lines)

            if lines:

def _display_common_metadata(metadatas, lines):
    if len(metadatas) < 2:
        return

    for metadata in metadatas:
        # don't display name as metadata, it's already displayed
        metadata.pop('name', None)

    common_metadata = _common_metadata(metadatas)
    if common_metadata:
        format_title('Common metadata', lines=lines)
        empty_line(lines)

        format_metadata(common_metadata, lines=lines)

    for key in common_metadata:
        for metadata in metadatas:
            metadata.pop(key, None)

display_runs_args=display_runs_args)

            if bench_lines:
                empty_line(lines)
                lines.extend(bench_lines)

            if lines:
                bench_lines = lines
                lines = []

                if show_filename and item.suite is not suite:
                    suite = item.suite
                    format_title(item.filename, 1, lines=lines)

                    if stats and len(suite) > 1:
                        empty_line(lines)

                        duration = suite.get_total_duration()
                        lines.append("Number of benchmarks: %s" % len(suite))
                        lines.append("Total duration: %s" % format_seconds(duration))
                        dates = suite.get_dates()
                        if dates:
                            start, end = dates
                            lines.append("Start date: %s" % format_datetime(start, microsecond=False))
                            lines.append("End date: %s" % format_datetime(end, microsecond=False))

                if show_name:
                    format_title(item.name, 2, lines=lines)

                empty_line(lines)
                lines.extend(bench_lines)