public static final KeyTemplate aes256CtrHmacSha256Template() {
    return exceptionIsBug(
        () ->
            KeyTemplate.createFrom(
                AesCtrHmacAeadParameters.builder()
                    .setAesKeySizeBytes(32)
                    .setHmacKeySizeBytes(32)
                    .setIvSizeBytes(16)
                    .setTagSizeBytes(32)
                    .setHashType(AesCtrHmacAeadParameters.HashType.SHA256)
                    .setVariant(AesCtrHmacAeadParameters.Variant.TINK)
                    .build()));
  }
@return a {@link KeyTemplate} that generates new instances of AES-CTR-HMAC-AEAD keys with the
    following parameters:
    <ul>
      <li>AES key size: 32 bytes
      <li>AES CTR IV size: 16 byte
      <li>HMAC key size: 32 bytes
      <li>HMAC tag size: 32 bytes
      <li>HMAC hash function: SHA256
    </ul>
java_src/src/main/java/com/google/crypto/tink/aead/AesCtrHmacAeadKeyManager.java