syntax_data: {"ast_node_type":"variable","tokens":[{"end":80,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                             let (args, opt_ty) = match predicate.skip_binder() {
context_before:                         .filter_map(|predicate| {
context_after:                                 ty::ExistentialPredicate::Trait(tr) => (tr.args, None),