public static final KeyTemplate rawAes256SivTemplate() {
    return exceptionIsBug(
        () ->
            KeyTemplate.createFrom(
                AesSivParameters.builder()
                    .setKeySizeBytes(KEY_SIZE_IN_BYTES)
                    .setVariant(AesSivParameters.Variant.NO_PREFIX)
                    .build()));
  }
@return A {@code KeyTemplate} that generates new instances of AES-SIV-CMAC keys. Keys generated
    from this template create ciphertexts compatible with other libraries.
java_src/src/main/java/com/google/crypto/tink/daead/AesSivKeyManager.java