{"ast_node_type":"variable","tokens":[{"end":69,"kind":"keyword","start":0,"text":"let"}]}
                    let abs_lane_diff = fx.bcx.ins().iabs(lane_diff);
                    let lane_diff = fx.bcx.ins().isub(a_lane, b_lane);
                    let abs_lane_diff = fx.bcx.ins().uextend(types::I64, abs_lane_diff);