Function load_icon 

pub fn load_icon<'a>(
    id: impl Into<IconId<'a>>,
    set: IconSet,
) -> Option<IconData>

Load an icon using the given set with default per-set options.

For set-specific options (freedesktop theme, fg_color), construct the specific loader directly and chain the relevant methods.

Each set needs its loader’s feature (see the loaders); None without it.