contentHandlerServiceTracker.open();
StreamHandlerFactory.secureAction.open(contentHandlerServiceTracker);
	public ContentHandlerProxy(String contentType, ServiceReference reference, BundleContext context) {		this.context = context;		this.contentType = contentType;		if (reference != null) {			setNewHandler(reference, getRank(reference));		}		//In this case, the proxy is constructed for a Content Handler that is not currently registered. 		//Use the DefaultContentHandler until a ContentHandler for this mime-type is registered		else {			realHandler = new DefaultContentHandler();		}		contentHandlerServiceTracker = new ServiceTracker(context, ContentHandler.class.getName(), this);		contentHandlerServiceTracker.open();	}