syntax_data: {"ast_node_type":"other","tokens":[{"end":73,"kind":"keyword","start":0,"text":"smallvec![(trait_ref,"}]}
source_snippet:         smallvec![(trait_ref, emit_vptr_on_new_entry, maybe_iter(None))];
context_before:     let mut stack: SmallVec<[(ty::TraitRef<'tcx>, _, _); 5]> =
context_after:     visited.insert(predicate);