@Test
  public void testRegisterKeyManager_sameNewKeyAllowed_shouldWork() throws Exception {
    // Skip test if in FIPS mode, as registerKeyManager() is not allowed in FipsMode.
    Assume.assumeFalse(TinkFips.useOnlyFips());

    String typeUrl = "someOtherTypeUrl";
    Registry.registerKeyManager(new CustomAeadKeyManager(typeUrl));
    Registry.registerKeyManager(new CustomAeadKeyManager(typeUrl), true);
  }
Returns the type URL that identifies the key type of keys managed by this KeyManager.
java_src/src/test/java/com/google/crypto/tink/RegistryTest.java