why we're doing this and how to upgrade.

    The OkHttp 3.12.x branch will be our long-term branch for Android 2.3+ (API level 9+) and Java
    7+. These platforms lack support for TLS 1.2 and should not be used. But because upgrading is
    difficult we will backport critical fixes to the 3.12.x branch through December 31, 2021. (This
    commitment was originally through December 31, 2020; we have since extended it.)

            V entryValue = e.getValue();

            if (entryValue != null) {
              // TODO(kak): Remove this branch
            } else if (isCollected(e)) {
              // TODO(kak): Remove this branch
            } else {
              return null;
            }

            ++modCount;
            E newFirst = removeFromChain(first, e);

	// Fetch buffer for I/O, returns from the pool if not allocates a new one and returns.
	var buffer []byte
	switch size := data.Size(); {
	case size == 0:
		buffer = make([]byte, 1) // Allocate at least a byte to reach EOF
	case size >= fi.Erasure.BlockSize:
		buffer = globalBytePoolCap.Load().Get()
		defer globalBytePoolCap.Load().Put(buffer)
	case size < fi.Erasure.BlockSize:

			versionID := fi.VersionID
			if versionID == "" {
				versionID = nullVersionID
			}

			// PR #11758 used DataDir, preserve it
			// for users who might have used master
			// branch
			xlMeta.data.remove(versionID, dataDir)

			// We need to attempt delete "dataDir" on the disk
			// due to a CopyObject() bug where it might have
			// inlined the data incorrectly, to avoid a situation

     * this client silently recovers from the following problems:
     *
     * * **Unreachable IP addresses.** If the URL's host has multiple IP addresses,
     *   failure to reach any individual IP address doesn't fail the overall request. This can
     *   increase availability of multi-homed services.
     *
     * * **Stale pooled connections.** The [ConnectionPool] reuses sockets

 * q: cute #puppies
 * f: images
 * ```
 *
 * In addition to composing URLs from their component parts and decomposing URLs into their
 * component parts, this class implements relative URL resolution: what address you'd reach by
 * clicking a relative link on a specified page. For example:
 *
 * ```java
 * HttpUrl base = HttpUrl.parse("https://www.youtube.com/user/WatchTheDaily/videos");
 * HttpUrl link = base.resolve("../../watch?v=cbP2N1BQdYc");

	serverPools.FilterMaxUsed(100 - (100 * diskReserveFraction))
	total := serverPools.TotalAvailable()
	if total == 0 {
		return -1
	}
	// choose when we reach this many
	choose := rand.Uint64() % total
	atTotal := uint64(0)
	for _, pool := range serverPools {
		atTotal += pool.Available
		if atTotal > choose && pool.Available > 0 {
			return pool.Index
		}
	}