{"ast_node_type":"other","tokens":[{"end":76,"kind":"keyword","start":0,"text":"ty::ExistentialPredicate::AutoTrait(def_id)"}]}
                ty::ExistentialPredicate::AutoTrait(def_id) => Some(def_id),
                ty::ExistentialPredicate::Trait(tr) => Some(tr.def_id),
                // An associated type projection necessarily comes with