byte[] keybytes = key.getEncoded();
        Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
        cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(keybytes, "AES"), new IvParameterSpec(ZERO_IV, 0, ZERO_IV.length));
        if ( constant.length != cipher.getBlockSize() ) {
            constant = expandNFold(constant, cipher.getBlockSize());

   * requests on the same socket, and server-push. HTTP/1.1 semantics are layered on HTTP/2.
   *
   * HTTP/2 requires deployments of HTTP/2 that use TLS 1.2 support
   * [CipherSuite.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256], present in Java 8+ and Android 5+.
   * Servers that enforce this may send an exception message including the string
   * `INADEQUATE_SECURITY`.
   */
  HTTP_2("h2"),

  /**

Connection: keep-alive
Location: https://publicobject.com/helloworld.txt

INFO: Sending request https://publicobject.com/helloworld.txt on Connection{publicobject.com:443, proxy=DIRECT hostAddress=54.187.32.157 cipherSuite=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA protocol=http/1.1}
User-Agent: OkHttp Example
Host: publicobject.com
Connection: Keep-Alive
Accept-Encoding: gzip

INFO: Received response for https://publicobject.com/helloworld.txt in 80.9ms