code: private Document parseIddFile(String serviceName) {
  
  		String iddFileName = serviceName + ".xml";
  
      	if (isIddAsResource()) {
      		InputStream is = resourceLoader.getResourceAsStream(iddFileName);
      		if (is == null) {
      			throw new RuntimeException("Cannot open IDD resource named '" + iddFileName + "'");
      		}
      		return XmlUtil.parse(is, resolver);
      	}
      	else {
      		File iddFile = new File( new File(getBaseDir(), RESOURCES_DIR), iddFileName);
      		if (!iddFile.exists()) {
      			throw new RuntimeException("Cannot open IDD file named '" + iddFileName + "'");
      		}
      		return XmlUtil.parse(iddFile, resolver);
      	}
  	}
docs: Find, open and parse the IDD implied by the specified service name. Reads either an explicit
  file or else a resource based on {@link #iddAsResource} flag.
  <p>
  The implied name is simply the service name + ".xml".