Function prepare_outline_glyph 

fn prepare_outline_glyph<'a>(
    glyph: Glyph,
    font_id: u64,
    font_index: u32,
    outline_cache: &'a mut OutlineCacheSession<'_>,
    size: Size,
    initial_transform: Affine,
    run_transform: Affine,
    outline_glyph: &OutlineGlyph<'a>,
    hinting_instance: Option<&HintingInstance>,
    normalized_coords: &[NormalizedCoord],
) -> (GlyphType<'a>, Affine)