def register_mime(shortname, mime_types):
    """
    Register a new mime type.
    Usage example:
        mimerender.register_mime('svg', ('application/x-svg', 'application/svg+xml',))
    After this you can do:
        @mimerender.mimerender(svg=render_svg)
        def GET(...
            ...
    """
    if shortname in _MIME_TYPES:
        raise MimeRenderException('"%s" has already been registered'%shortname)
    _MIME_TYPES[shortname] = mime_types