public async Task ObjectForPrimaryKey_Sequential()
        {
            await GeneratePerfRangesForBlock2(async (cache, size, keys) =>
            {
                var st      = new Stopwatch();
                var toFetch = Enumerable.Range(0, size)
                              .Select(_ => keys[prng.Next(0, keys.Count - 1)])
                              .ToArray();

                await Task.Run(() =>
                {
                    st.Start();

                    var realmThread = new RealmThread(cache.Config);
                    realmThread.BeginInvoke(threadSafeRealm =>
                    {
                        foreach (var v in toFetch)
                        {
                            threadSafeRealm.ObjectForPrimaryKey <KeyValueRecord>(v);
                        }
                    });
                    realmThread.Dispose();

                    st.Stop();
                });

                return(st.ElapsedMilliseconds);
            });
        }