@Override
    public TraceMetadataLoaderService get() {
        logger.info("Registering trace metadata to providers");
        TraceMetadataRegistrar.registerServiceTypes(serviceTypeRegistry);
        TraceMetadataRegistrar.registerAnnotationKeys(annotationKeyRegistry);
        return new DefaultTraceMetadataLoaderService(serviceTypeRegistry, annotationKeyRegistry, annotationKeyMatcherRegistry);
    }
@author Woonduk Kang(emeroad)
@author HyunGil Jeong
agent-module/profiler/src/main/java/com/navercorp/pinpoint/profiler/context/provider/plugin/TraceMetadataLoaderServiceProvider.java