def format_unix_time(unix_time, style=None):
    """
    Formats unix time to Discord'stimestamp  markdown format.
    
    For formatting details please check out ``TIMESTAMP_STYLES``, which contains the usable styles.
    
    Parameters
    ----------
    unix_time : `int`
        The datetime to format.
    style : `None` or `str`, `optional
        Format code to use. They are listed within ``TIMESTAMP_STYLES``.
    
    Returns
    -------
    formatted_string : `str`
    """
    if style is None:
        formatted_string = f'<t:{unix_time}>'
    else:
        formatted_string = f'<t:{unix_time}:{style}>'
    
    return formatted_string