// -------------------------------------------------------------------------
 public void test_containsAny() {
   ExternalIdSearch test = ExternalIdSearch.of(_id11, _id12);
   assertEquals(true, test.containsAny(ImmutableSet.of(_id11, _id12)));
   assertEquals(true, test.containsAny(ImmutableSet.of(_id11)));
   assertEquals(true, test.containsAny(ImmutableSet.of(_id12)));
   assertEquals(false, test.containsAny(ImmutableSet.of(_id21)));
   assertEquals(false, test.containsAny(ImmutableSet.of()));
 }
 @Test(expectedExceptions = IllegalArgumentException.class)
 public void test_containsAny_null() {
   ExternalIdSearch test = ExternalIdSearch.of(_id11, _id12);
   test.containsAny(null);
 }