private Filter<URL> newPluginTypeProviderUrlFilter() {
        final URL agentAttached = agentAttached();
        if (agentAttached != null) {
            logger.info("Attached Agent found:{}", agentAttached);
            return new AgentLibraryPluginFilter();
        }
        return new Filter<URL> () {

            @Override
            public boolean filter(URL value) {
                return NOT_FILTERED;
            }
        };
    }
@author Woonduk Kang(emeroad)
@author HyunGil Jeong
@author Taejin Koo
commons-server/src/main/java/com/navercorp/pinpoint/common/server/util/ServerTraceMetadataLoaderService.java