syntax_data: {"ast_node_type":"other","tokens":[{"end":115,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// and a concrete type `self_ty`, returns a full predicate where the existentially quantified variable `?Self`
context_before:     /// Given an existential predicate like `?Self: PartialEq<u32>` (e.g., derived from `dyn PartialEq<u32>`),
context_after:     /// has been replaced with `self_ty` (e.g., `self_ty: PartialEq<u32>`, in our example).