syntax_data: {"ast_node_type":"variable","tokens":[{"end":43,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:     let (items, impl_def_id) = match item {
context_before:     debug!(?item, ?cause, ?pred, "extended_cause_with_original_assoc_item_obligation");
context_after:         Some(hir::Item { kind: hir::ItemKind::Impl(impl_), owner_id, .. }) => {