@Test
 public void testTraitPrerequisiteBuilder() throws Exception {
   String xml = "<trait id=\"Larceny\" value=\"3\"/>";
   Element rootElement = DocumentUtilities.read(xml).getRootElement();
   GenericTrait trait = builder.build(rootElement);
   assertEquals(AbilityType.Larceny, trait.getType());
   assertEquals(3, trait.getCurrentValue());
 }
 @Test(expected = PersistenceException.class)
 public void testValueMissing() throws Exception {
   String xml = "<trait id=\"Larceny\" />";
   Element rootElement = DocumentUtilities.read(xml).getRootElement();
   builder.build(rootElement);
 }