syntax_data: {"ast_node_type":"other","tokens":[{"end":93,"kind":"keyword","start":0,"text":"(ty::ExistentialPredicate::Trait(a),"}]}
source_snippet:                 (ty::ExistentialPredicate::Trait(a), ty::ExistentialPredicate::Trait(b)) => {
context_before:             iter::zip(a, b).map(|(ep_a, ep_b)| match (ep_a.skip_binder(), ep_b.skip_binder()) {
context_after:                     Ok(ep_a.rebind(ty::ExistentialPredicate::Trait(