/**
     * Extension header set by OkHttp specifying the timestamp when the cached HTTP response was
     * first received.
     */
    private var receivedResponseMillis = 0L

    /** Etag of the cached response. */
    private var etag: String? = null

    /** Age of the cached response. */
    private var ageSeconds = -1

    /**
     * Returns true if computeFreshnessLifetime used a heuristic. If we used a heuristic to serve a

   *
   * @since 28.2
   */
  public static final String CROSS_ORIGIN_OPENER_POLICY = "Cross-Origin-Opener-Policy";

  /** The HTTP {@code ETag} header field name. */
  public static final String ETAG = "ETag";

  /** The HTTP {@code Expires} header field name. */
  public static final String EXPIRES = "Expires";

  /** The HTTP {@code Last-Modified} header field name. */

      Header("content-length", ""),
      Header("content-location", ""),
      Header("content-range", ""),
      Header("content-type", ""),
      Header("cookie", ""),
      Header("date", ""),
      Header("etag", ""),
      Header("expect", ""),
      Header("expires", ""),
      Header("from", ""),
      Header("host", ""),
      Header("if-match", ""),
      Header("if-modified-since", ""),