docs: private String buildEncryptionMetadataJSON(String iv64, String key64)
    {
      return String.format("{\"EncryptionMode\":\"FullBlob\",\"WrappedContentKey\""
                           + ":{\"KeyId\":\"symmKey1\",\"EncryptedKey\":\"%s\""
                           + ",\"Algorithm\":\"AES_CBC_256\"},\"EncryptionAgent\":"
                           + "{\"Protocol\":\"1.0\",\"EncryptionAlgorithm\":"
                           + "\"AES_CBC_256\"},\"ContentEncryptionIV\":\"%s\""
                           + ",\"KeyWrappingMetadata\":{\"EncryptionLibrary\":"
                           + "\"Java 5.3.0\"}}", key64, iv64);
    }