syntax_data: {"ast_node_type":"other","tokens":[{"end":73,"kind":"keyword","start":0,"text":"pub"}]}
source_snippet:     pub region_constraints: Vec<ty::OutlivesPredicate<I, I::GenericArg>>,
context_before: pub struct ExternalConstraintsData<I: Interner> {
context_after:     pub opaque_types: Vec<(ty::OpaqueTypeKey<I>, I::Ty)>,