# Chaikins Volatility (CVI) ``` use cvi_rs::CVI; use ta_common::traits::Indicator; let mut cvi = CVI::new(5); assert_eq!(cvi.next([82.15, 81.29]), None); assert_eq!(cvi.next([81.89, 80.64]), None); assert_eq!(cvi.next([83.03, 81.31]), None); assert_eq!(cvi.next([83.30, 82.65]), None); assert_eq!(cvi.next([83.85, 83.07]), None); assert_eq!(cvi.next([83.90, 83.11]), Some(4.464542061441478)); assert_eq!(cvi.next([83.33, 82.49]), Some(-11.219187762397418)); assert_eq!(cvi.next([84.30, 82.30]), Some(1.5637860082306099)); assert_eq!(cvi.next([84.84, 84.15]), Some(2.5210712792415677)); assert_eq!(cvi.next([85.00, 84.11]), Some(5.682116365544989)); assert_eq!(cvi.next([85.90, 84.03]), Some(44.08805917058712)); assert_eq!(cvi.next([86.58, 85.39]), Some(43.3166782081056)); assert_eq!(cvi.next([86.98, 85.76]), Some(-0.4937226078952195)); assert_eq!(cvi.next([88.00, 87.17]), Some(3.994412353229816)); assert_eq!(cvi.next([87.87, 87.01]), Some(1.8239886289963296)); ```