@Test
  public void legacyFullPrfNotRegistered_fails() throws Exception {
    MutablePrimitiveRegistry.resetGlobalInstanceTestOnly();

    KeysetHandle keysetHandle =
        getKeysetHandleFromKeyNoSerialization(HMAC_LEGACY_PRF_TEST_VECTORS[0].key);

    assertThrows(GeneralSecurityException.class, () -> keysetHandle.getPrimitive(PrfSet.class));
  }
Verifies that LegacyFullPrf is correctly integrated with the Tink ecosystem.
java_src/src/test/java/com/google/crypto/tink/prf/internal/LegacyFullPrfIntegrationTest.java