syntax_data: {"ast_node_type":"other","tokens":[{"end":64,"kind":"keyword","start":0,"text":"ty::ExistentialPredicate::AutoTrait(def_id)"}]}
source_snippet:                 ty::ExistentialPredicate::AutoTrait(def_id) => {
context_before:                 // Check that b_ty's auto traits are present in a_ty's bounds.
context_after:                     if !a_auto_traits.contains(&def_id) {