private String getString(String key) {
        ResourceBundle messageRB = this.messageRB;
        if (messageRB == null) {
            try {
                this.messageRB = messageRB =
                    ResourceBundle.getBundle(
                          "com.sun.tools.javadoc.resources.javadoc");
            } catch (MissingResourceException e) {
                throw new Error("Fatal: Resource for javadoc is missing");
            }
        }
        return messageRB.getString(key);
    }