public void stopSpan(DebuggingSpan span) {
        if (debug) {
            span.setEndTime(System.nanoTime());
            span.setDuration(span.getEndTime() - span.getStartTime());
            if (spanStack.isEmpty()) {
                return;
            }
            spanStack.pop();
        }
    }
Use for transform the other Span to DebuggingSpan, such as BanyanDB trace span.
The start time , end time, duration, parent span id should be set manually.
@param operation operation
@return DebuggingSpan
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/query/type/debugging/DebuggingTraceContext.java