docs: static void writeGlobalSettings(BufferedWriter writer) throws IOException {
          GlobalSettings globalSettings = GlobalSettings.getInstance();
          writer.write(XML_START_TAG);
          XMLUtils.writeXmlAttribute(SOUND_ENABLED, XMLUtils.xmlFromBoolean
                  (globalSettings.isSoundEnabled()), writer);
          XMLUtils.writeXmlAttribute(ONSCREEN, XMLUtils.xmlFromBoolean(globalSettings.isOnScreen())
                  , writer);
          XMLUtils.writeXmlAttribute(PREVIEW, XMLUtils.xmlFromBoolean(globalSettings.getPreview()),
                  writer);
          writer.write(XMLUtils.ELEMENT_END);
      }