syntax_data: {"ast_node_type":"other","tokens":[{"end":48,"kind":"keyword","start":0,"text":"assert!(!self_ty.has_escaping_bound_vars());"}]}
source_snippet:     assert!(!self_ty.has_escaping_bound_vars());
context_before: ) -> (ty::TraitRef<'tcx>, Ty<'tcx>, Ty<'tcx>) {
context_after:     let trait_ref = ty::TraitRef::new(tcx, fn_trait_def_id, [self_ty, sig.resume_ty]);