syntax_data: {"ast_node_type":"other","tokens":[{"end":110,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// Given an existential predicate like `?Self: PartialEq<u32>` (e.g., derived from `dyn PartialEq<u32>`),
context_before: impl<I: Interner> ty::Binder<I, ExistentialPredicate<I>> {
context_after:     /// and a concrete type `self_ty`, returns a full predicate where the existentially quantified variable `?Self`