if (!classScreener.matches(urlToParse.toString())) return null;
		public JavaClass getNextClass() throws IOException, InterruptedException {			if (url == null)				return null;			if (Thread.interrupted())				throw new InterruptedException();			URL urlToParse = url;			url = null; // don't return it next time			try {				return parseClass(urlToParse);			} catch (ClassFormatException e) {				throw new ClassFormatException("Invalid class file format for " +				        url.toString() + ": " + e.getMessage());			}		}