*
 * [ietf_alpn]: http://tools.ietf.org/html/draft-ietf-tls-applayerprotoneg
 */
enum class Protocol(private val protocol: String) {
  /**
   * An obsolete plaintext framing that does not use persistent sockets by default.
   */
  HTTP_1_0("http/1.0"),

  /**
   * A plaintext framing that includes persistent connections.
   *
   * This version of OkHttp implements [RFC 7230][rfc_7230], and tracks revisions to that spec.
   *