@Override
    public Trace continueTraceObject(Trace trace) {
        final Reference<Trace> reference = checkAndGet();

        bind(reference, trace);
        return trace;
    }
Return Trace object AFTER validating whether it can be sampled or not.

@return Trace
agent-module/profiler/src/main/java/com/navercorp/pinpoint/profiler/context/DefaultTraceFactory.java