{"ast_node_type":"variable","tokens":[{"end":85,"kind":"keyword","start":0,"text":"let"}]}
                let def_id = cx.typeck_results().type_dependent_def_id(expr.hir_id)?;
                // Find problematic calls to `MaybeUninit::assume_init`.
                if cx.tcx.is_diagnostic_item(sym::assume_init, def_id) {