.addHeader("Last-Modified: " + formatDate(-1, TimeUnit.HOURS))
        .addHeader("Expires: " + formatDate(1, TimeUnit.HOURS))
        .body("ABC")
        .build(),
    )
    server.enqueue(
      MockResponse.Builder()
        .addHeader("Last-Modified: " + formatDate(-5, TimeUnit.MINUTES))
        .addHeader("Expires: " + formatDate(2, TimeUnit.HOURS))
        .body("DEF")
        .build(),
    )

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

    /**
     * Returns true if computeFreshnessLifetime used a heuristic. If we used a heuristic to serve a
     * cached response older than 24 hours, we are required to attach a warning.
     */
    private fun isFreshnessLifetimeHeuristic(): Boolean {
      return cacheResponse!!.cacheControl.maxAgeSeconds == -1 && expires == null
    }

    init {