fn parse_font_spec_identifiers<'i>(parser: &mut Parser<'i, '_>) -> Result<Font, ParseError<'i>> {
/// CSS Writing Modes 3: <https://www.w3.org/TR/css-writing-modes-3/#propdef-glyph-orientation-vertical>
fn parse<'i>(parser: &mut Parser<'i, '_>) -> Result<GlyphOrientationVertical, ParseError<'i>> {