public void testWritingTrekBuddyExtensions() throws IOException, JAXBException {
slash.navigation.gpx.binding11.ObjectFactory gpxFactory = new slash.navigation.gpx.binding11.ObjectFactory();
slash.navigation.gpx.trekbuddy.ObjectFactory tbFactory = new slash.navigation.gpx.trekbuddy.ObjectFactory();
ExtensionsType extensionsType = gpxFactory.createExtensionsType();
extensionsType.getAny().add(tbFactory.createSpeed(formatBigDecimal(123.45, 2)));
GpxType gpx = gpxFactory.createGpxType();
assertNotNull(gpx);
gpx.setExtensions(extensionsType);
assertNotNull(gpx);
StringWriter writer = new StringWriter();
GpxUtil.marshal11(gpx, writer);
String string = writer.toString();
assertTrue(string.contains("<nmea:speed>123.45</nmea:speed>"));