syntax_data: {"ast_node_type":"other","tokens":[{"end":70,"kind":"keyword","start":0,"text":"for"}]}
source_snippet:         for &impl_def_id in tcx.crate_incoherent_impls((cnum, simp)) {
context_before:     for cnum in iter::once(LOCAL_CRATE).chain(tcx.crates(()).iter().copied()) {
context_after:             impls.push(impl_def_id)