Function ensure_shared_sfx 

pub fn ensure_shared_sfx(
    key: &str,
    effect: &SfxEntry,
    sfx_dir: &Path,
    cfg: &SfxConfig,
    backend: &mut dyn SfxBackend,
) -> Result<PathBuf>

ensure_shared_sfx(key, effect, sfx_dir, defaults, show=, backend=).