class TraceJsonService {

    @GET(path = "/backend/trace/header", permission = "agent:trace")
    String getHeader(@BindAgentId String agentId, @BindRequest HeaderRequest request)
            throws Exception {
        String headerJson = traceCommonService.getHeaderJson(agentId, request.traceId(),
                request.checkLiveTraces());
        if (headerJson == null) {
            logger.debug("no trace found for agent id '{}' and trace id '{}'", agentId,
                    request.traceId());
            return "{\"expired\":true}";
        } else {
            return headerJson;
        }
    }

      TraceJsonService(TraceCommonService traceCommonService);

}