Convert epoch timestamp to a localized datetime string.

    Arguments
    ---------
    timestamp : int
        The timestamp to convert.
    timezone_name : datetime.timezone
        The timezone of the desired local time.
    fmt : str
        The format of the output string.

    Returns
    -------
    str
        The localized datetime string.

def timestamp_to_local_time_str(
        timestamp, timezone_name, fmt="yyyy-MM-dd HH:mm:ss"):
    """Convert epoch timestamp to a localized datetime string.

    Arguments
    ---------
    timestamp : int
        The timestamp to convert.
    timezone_name : datetime.timezone
        The timezone of the desired local time.
    fmt : str
        The format of the output string.

    Returns
    -------
    str
        The localized datetime string.
    """
    localized_d = timestamp_to_local_time(timestamp, timezone_name)
    localized_datetime_str = localized_d.format_datetime(fmt)
    return localized_datetime_str