}

    /**
     * Adds to the total processing time of this document list.
     *
     * @param processingTime the processing time to add in milliseconds
     */
    public void addProcessingTime(final long processingTime) {
        this.processingTime += processingTime;
    }

    /**
     * Returns a string representation of this DocList including metrics and content.
     *

            docList.addContentSize(contentSize);
            final long processingTime = systemHelper.getCurrentTimeAsLong() - startTime;
            docList.addProcessingTime(processingTime);
            if (logger.isDebugEnabled()) {
                logger.debug("Added document (size={}, time={}ms). Document cache count: {}",

                    docList.addContentSize(contentSize);
                    final long processingTime = systemHelper.getCurrentTimeAsLong() - startTime;
                    docList.addProcessingTime(processingTime);
                    if (logger.isDebugEnabled()) {
                        logger.debug("Added the document({}, {}ms). The number of a document cache is {} (size: {}).",