@Override
    public SpanEventRecorder currentSpanEventRecorder() {
        SpanEvent spanEvent = callStack.peek();
        if (spanEvent == null) {
            if (logger.isWarnEnabled()) {
                stackDump("call stack is empty");
            }
            // make dummy.
            spanEvent = dummySpanEvent();
        }

        return wrappedSpanEventRecorder(this.wrappedSpanEventRecorder, spanEvent);
    }
Get current TraceID. If it was not set this will return null.

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