syntax_data: {"ast_node_type":"other","tokens":[{"end":53,"kind":"keyword","start":0,"text":"for"}]}
source_snippet:             for &(impl_def_id, simplified_self_ty) in
context_before:         for &cnum in tcx.crates(()).iter() {
context_after:                 tcx.implementations_of_trait((cnum, trait_id)).iter()