private void PullType(Type t)
        {
            var      now      = DateTime.Now;
            DateTime?lastPull = null;

            lock (m_pullTimestamps)
            {
                if (m_pullTimestamps.ContainsKey(t))
                {
                    lastPull = m_pullTimestamps[t];
                }
            }

            var items = RemoteStore.GetMultiple(t, lastPull);

            // append to local store
            LocalStore.StoreMultiple(items);

            lock (m_pullTimestamps)
            {
                if (m_pullTimestamps.ContainsKey(t))
                {
                    m_pullTimestamps[t] = now;
                }
                else
                {
                    m_pullTimestamps.Add(t, now);
                }
            }
        }