syntax_data: {"ast_node_type":"other","tokens":[{"end":47,"kind":"keyword","start":0,"text":"supertrait_span:"}]}
source_snippet:         supertrait_span: <I as Interner>::Span,
context_before:         clause: <I as Interner>::Clause,
context_after:         _parent_trait_pred: crate::Binder<I, crate::TraitPredicate<I>>,