code: public void save(XMLWriter w) throws KNXMLException
  	{
  		/* XML layout:
  		 <datapoint stateBased=[true|false] name=string mainNumber=int dptID=string
  		 priority=string>
  		 knxAddress
  		 ...
  		 </datapoint>
  		*/
  		final List att = new ArrayList();
  		att.add(new Attribute(ATTR_STATEBASED, Boolean.toString(stateBased)));
  		att.add(new Attribute(ATTR_NAME, name));
  		att.add(new Attribute(ATTR_MAINNUMBER, Integer.toString(mainNo)));
  		att.add(new Attribute(ATTR_DPTID, dptID == null ? "" : dptID));
  		att.add(new Attribute(ATTR_PRIORITY, priority.toString()));
  		w.writeElement(TAG_DATAPOINT, att, null);
  		main.save(w);
  		doSave(w);
  		w.endElement();
  	}
docs: Saves this datapoint in XML format to the supplied XML writer.
  <p>
  
  @param w a XML writer
  @throws KNXMLException on error saving this datapoint