modify

@@ -401,7 +401,7 @@ export function sortList(arr, key) {
   });
 }
 
-// 获取计算元素的属性的margin + padding + clientHeight
+// 获取计算元素的属性的marginTop + marginBottom + paddingTop + paddingBottom值
 function getPropertyValue(el) {
   let style, marginTop, marginBottom, paddingTop, paddingBottom;
   style = window.getComputedStyle(el, null);