public static final KeyTemplate aes128GcmSivTemplate() {
    return exceptionIsBug(
        () ->
            KeyTemplate.createFrom(
                AesGcmSivParameters.builder()
                    .setKeySizeBytes(16)
                    .setVariant(AesGcmSivParameters.Variant.TINK)
                    .build()));
  }
Creates and returns a {@link KeyTemplate} that generates new instances of AES-GCM-SIV with the
following parameters:

<ul>
  <li>Key size: 16 bytes
  <li>Prefix type: {@link KeyTemplate.OutputPrefixType#TINK}
</ul>
java_src/src/main/java/com/google/crypto/tink/aead/AesGcmSivKeyManager.java