{"ast_node_type":"other","tokens":[{"end":81,"kind":"keyword","start":0,"text":"///"}]}
/// that the `ref_id` is for. The `impl_id` maps to the "self type" of this impl.
/// Resolution maps each `TraitRef`'s `ref_id` to its defining trait; that's all
/// If this impl is an `ItemKind::Impl`, the `impl_id` is redundant (it could be the