Adding a method does not require updating the object structure, but it does require updating the class structure, which is also present on the heap.
添加一个方法并不要求更新对象的结构，但确实是需要更新类的结构的，这也会体现在堆上。
2
Each object allocated on the GC heap has an 8-byte overhead (sync block + method table pointer).
每个在GC堆中分配的对象有一个8字节的头(同步块+方法表指针)。
3
Health Center collects comprehensive method profiles with an extremely low overhead, highlights contended locks, analyzes garbage collection and heap usage, and visualizes class loading activity.
Health Center以极低的开销收集广泛的方法摘要，突出显示争用锁，分析垃圾收集和堆使用情况，可视化类加载行为。