final ChatSource source = new ChatSource(i + 1, sourceList.get(i));
            source.setGoUrl(buildGoUrl(contextPath, source.getDocId(), queryId, requestedTime, i));
            assistantMessage.addSource(source);
        }
    }

    /**
     * Populates the url_link field in the document map if not already present.
     *
     * @param doc the document map
     */