code: public String getRuntime() throws AppEngineException {
      String runtime = getText(getNode(document, "appengine-web-app", "runtime"));
      if (runtime == null) {
        runtime = "java7"; // the default runtime when not specified.
      }
      return runtime;
    }
docs: Returns runtime from the &lt;runtime&gt; element of the appengine-web.xml or the default one
  when it is missing.