syntax_data: {"ast_node_type":"other","tokens":[{"end":44,"kind":"keyword","start":0,"text":"(trait_ref,"}]}
source_snippet:     (trait_ref, sig.yield_ty, sig.return_ty)
context_before:     let trait_ref = ty::TraitRef::new(tcx, fn_trait_def_id, [self_ty, sig.resume_ty]);
context_after: }