private NodeHistogramSummary createEmptyNodeHistogramSummary(ServerGroupListFactory serverGroupListFactory, Application application, Range range) {
        ServerGroupList serverGroupList = serverGroupListFactory.createEmptyNodeInstanceList();
        NodeHistogram emptyNodeHistogram = NodeHistogram.empty(application, range);
        return new NodeHistogramSummary(application, serverGroupList, emptyNodeHistogram);
    }
@author HyunGil Jeong
@author jaehong.kim
web/src/main/java/com/navercorp/pinpoint/web/applicationmap/service/ResponseTimeHistogramServiceImpl.java