private void EnsureCacheUpdated()
        {
            lock (cacheLock)
            {
                if (cacheLastUpdated.AddMinutes(1) > VirtualDateTime.Now)
                {
                    return;
                }

                CustomLogger.Information("Starting cache update (AdminSearchService.StartCacheUpdateThread)");

                _cachedOrganisations = LoadAllOrganisations(dataRepository);
                _cachedUsers         = LoadAllUsers(dataRepository);

                cacheLastUpdated = VirtualDateTime.Now;

                CustomLogger.Information("Finished cache update (AdminSearchService.StartCacheUpdateThread)");
            }
        }