@Override
    public int getIndex() {
        if (isOverflow()) {
            return index + overflowIndex;
        }

        return index;
    }
@author netspider
@author Woonduk Kang(emeroad)
@author jaehong.kim
agent-module/profiler/src/main/java/com/navercorp/pinpoint/profiler/context/DefaultCallStack.java