public void computeEnhancements(ContentItem ci) throws EngineException {
HtmlExtractor extractor = new HtmlExtractor(htmlExtractorRegistry, htmlParser);
MGraph model = new SimpleMGraph();
ci.getLock().readLock().lock();
try {
extractor.extract(ci.getUri().getUnicodeString(), ci.getStream(),null, ci.getMimeType(), model);
} catch (ExtractorException e) {
throw new EngineException("Error while processing ContentItem "
+ ci.getUri()+" with HtmlExtractor",e);
} finally {
ci.getLock().readLock().unlock();