{"ast_node_type":"impl","tokens":[{"end":70,"kind":"keyword","start":0,"text":"//"}]}
        // This is something like `impl Trait1 for Trait2`. Illegal if
    if let ty::Dynamic(data, ..) = trait_ref.self_ty().kind() {
        // Trait1 is a supertrait of Trait2 or Trait2 is not dyn compatible.