解决方法
这样做是为了处理在超类中存在具有相同名称和签名的可覆盖方法时的一些罕见情况.虽然肯定有一个改进的地方,但可能是针对JDK 9的.
见https://bugs.openjdk.java.net/browse/JDK-8024368
Private methods always get a vtable entry to handle backward compatibility with classes – i.e. you can have the same name of a private method local to your class and also inherit a method of from your superclass,which will get inherited around the private method,by your child.
