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);