private String getSpanAttachedEventTagValue(List<KeyStringValuePair> values, String tagKey) {
        for (KeyStringValuePair pair : values) {
            if (Objects.equals(pair.getKey(), tagKey)) {
                return pair.getValue();
            }
        }
        return null;
    }
@param duration nullable unless for BanyanDB query from cold stage
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/query/TraceQueryService.java