private String errMsg(Object[] expected, Object[] actual) {
   return "Expected {"
       + ArrayFormat.format(expected)
       + "} but found {"
       + ArrayFormat.format(actual)
       + "}";
 }
 @Test
 public void testEntitySource() {
   ArrayTypeDescriptor descriptor = createArrayType("testEntitySourceType");
   descriptor.setSource(PersonSource.class.getName());
   Generator<Object[]> generator =
       (Generator<Object[]>)
           arrayTypeGeneratorFactory.createGenerator(
               descriptor, "testEntitySource", false, Uniqueness.NONE, context);
   generator.init(context);
   for (int i = 0; i < 2; i++) {
     Object[] product = GeneratorUtil.generateNonNull(generator);
     assertTrue(
         "Found: " + ArrayFormat.format(product),
         Arrays.equals(ALICE, product) || Arrays.equals(BOB, product));
   }
   assertUnavailable(generator);
 }