syntax_data: {"ast_node_type":"other","tokens":[{"end":44,"kind":"keyword","start":0,"text":"for"}]}
source_snippet:             for predicate in binder.iter() {
context_before:             let mut has_emitted = false;
context_after:                 if let ty::ExistentialPredicate::Trait(ref trait_ref) = predicate.skip_binder() {