@Test
  public void testAes128GcmTemplate() throws Exception {
    KeyTemplate template = AesGcmKeyManager.aes128GcmTemplate();
    assertThat(template.toParameters())
        .isEqualTo(
            AesGcmParameters.builder()
                .setIvSizeBytes(12)
                .setTagSizeBytes(16)
                .setKeySizeBytes(16)
                .setVariant(AesGcmParameters.Variant.TINK)
                .build());
  }
Test for AesGcmJce and its key manager.
java_src/src/test/java/com/google/crypto/tink/aead/AesGcmKeyManagerTest.java