How to use the pyperf._formatter.format_datetime function in pyperf

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)

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

        for line in output:
            print(line)

        if not output and only_checks:
            if len(data) == 1:

nrun = bench.get_nrun()
    nvalue = len(values)

    empty_line(lines)

    # Total duration
    duration = bench.get_total_duration()
    if duration:
        lines.append("Total duration: %s" % format_seconds(duration))

    # Start/End dates
    dates = bench.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))

    # Raw value minimize/maximum
    raw_values = bench._get_raw_values()
    lines.append("Raw value minimum: %s" % bench.format_value(min(raw_values)))
    lines.append("Raw value maximum: %s" % bench.format_value(max(raw_values)))
    lines.append('')

    # Number of values
    ncalibration_runs = sum(run._is_calibration() for run in bench._runs)
    lines.append("Number of calibration run: %s"
                 % format_number(ncalibration_runs))
    lines.append("Number of run with values: %s"
                 % (format_number(nrun - ncalibration_runs)))
    lines.append("Total number of run: %s" % format_number(nrun))
    lines.append('')

metadata['hostname'] = hostname

    # Boot time
    boot_time = None
    for line in read_proc("stat"):
        if not line.startswith("btime "):
            continue
        boot_time = int(line[6:])
        break

    if boot_time is None and psutil:
        boot_time = psutil.boot_time()

    if boot_time is not None:
        btime = datetime.datetime.fromtimestamp(boot_time)
        metadata['boot_time'] = format_datetime(btime)
        metadata['uptime'] = time.time() - boot_time

nrun = bench.get_nrun()
    nvalue = len(values)

    empty_line(lines)

    # Total duration
    duration = bench.get_total_duration()
    if duration:
        lines.append("Total duration: %s" % format_seconds(duration))

    # Start/End dates
    dates = bench.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))

    # Raw value minimize/maximum
    raw_values = bench._get_raw_values()
    lines.append("Raw value minimum: %s" % bench.format_value(min(raw_values)))
    lines.append("Raw value maximum: %s" % bench.format_value(max(raw_values)))
    lines.append('')

    # Number of values
    ncalibration_runs = sum(run._is_calibration() for run in bench._runs)
    lines.append("Number of calibration run: %s"
                 % format_number(ncalibration_runs))
    lines.append("Number of run with values: %s"
                 % (format_number(nrun - ncalibration_runs)))
    lines.append("Total number of run: %s" % format_number(nrun))
    lines.append('')

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)

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

        for line in output:
            print(line)

        if not output and only_checks: