/// A "Lifetime" is an annotation of the scope in which variable
/// can be used, e.g. `'a` in `&'a i32`.
-#[derive(Clone, Encodable, Decodable, Copy)]
+#[derive(Clone, Encodable, Decodable, Copy, PartialEq, Eq)]
pub struct Lifetime {
pub id: NodeId,
pub ident: Ident,