// If `id` itself is a mod named `m` with parent `p`, then
// returns `Some(id, m, p)`. If `id` has no mod in its parent
// chain, then returns `None`.
// If `id` itself is a mod named `m` with parent `p`, then
// returns `Some(id, m, p)`. If `id` has no mod in its parent
// chain, then returns `None`.