public boolean contains(T subItem) {
        return mSubItems != null && mSubItems.contains(subItem);
    }
<p>A helper to implement expandable item.</p>
<p>if you don't want to extent a class, you can also implement the interface IExpandable</p>
Created by luoxw on 2016/8/9.
common/src/main/java/com/sxjs/common/base/baseadapter/entity/AbstractExpandableItem.java