public void test_toString_nonEmpty() {
   ExternalIdSearch test = ExternalIdSearch.of(_id11, _id12);
   assertTrue(test.toString().contains(_id11.toString()));
   assertTrue(test.toString().contains(_id12.toString()));
 }
 public void test_toString_empty() {
   ExternalIdSearch test = ExternalIdSearch.of();
   assertTrue(test.toString().contains("[]"));
 }