@Override
    public String toString() {
      return name;
    }
Describes how the prefix is computed. There are two main possibilities: NO_PREFIX (empty
prefix) and TINK (prefix the ciphertext with 0x01 followed by a 4-byte key id in big endian.
java_src/src/main/java/com/google/crypto/tink/aead/LegacyKmsEnvelopeAeadParameters.java