@Test
 public void testFromExternalId() {
   String externalId = "A123";
   RecordRef ref =
       RecordReferences.from(RecordTypeEnum.ACCOUNT, externalId, RecordIdType.EXTERNAL)
           .createRef();
   assertEquals(externalId, ref.getExternalId());
   assertNull(ref.getInternalId());
 }
 @Test(expected = IllegalArgumentException.class)
 public void nullSafeFromNotIllegalArgument() throws Exception {
   RecordReferences.nulSafeFrom(null, "A126", null);
 }
 @Test
 public void nullSafeFromNotNull() throws Exception {
   assertNotNull(
       RecordReferences.nulSafeFrom(
           RecordTypeEnum.ASSEMBLY_UNBUILD, "A126", RecordIdType.INTERNAL));
 }
 @Test
 public void nullSafeFromNull() throws Exception {
   assertNull(RecordReferences.nulSafeFrom(null, null, null));
 }
 @Test(expected = IllegalArgumentException.class)
 public void testFromBadInputType() {
   RecordReferences.from(null, "A126", RecordIdType.INTERNAL);
 }
 @Test(expected = IllegalArgumentException.class)
 public void testFromBadInputId() {
   RecordReferences.from(RecordTypeEnum.ACCOUNT, null, RecordIdType.INTERNAL);
 }