reference
https://juejin.im/post/5a6db896518825732d7fd8e0
https://juejin.im/post/590ec765a22b9d0058fcfaa5
Comparison with a reference value
reference
https://juejin.im/post/5a6db896518825732d7fd8e0
https://juejin.im/post/590ec765a22b9d0058fcfaa5
Comparison with a reference value