code: private Document parseExtensionFile(String serviceName) {
  
  		String extensionFileName = serviceName + "-Extensions.xml";
  
      	if (isIddAsResource()) {
      		InputStream is = resourceLoader.getResourceAsStream(extensionFileName);
      		if (is != null) {
      			return XmlUtil.parse(is, resolver);
      		}
      		else {
      			return null;
      		}
      	}
      	else {
      		File extensionsFile = new File( new File(getBaseDir(), RESOURCES_DIR), extensionFileName);
      		if (extensionsFile.exists()) {
          		return XmlUtil.parse(extensionsFile, resolver);
      		}
      		else {
      			return null;
      		}
      	}
      }
docs: Find, open and parse the extensions xml file or null if it doesn't exist. Reads from
  file or resource based on {@link #iddAsResource} flag.
  <p>
  Name of extensions file should be ServiceName-Extensions.xml.