public ActiveDirectoryGroupCache()
{
this.securityIdentifierCache = new ConcurrentDictionary<SecurityIdentifier, Tuple<ADGroup, DateTime>>();
this.distinguishedNameCache = new ConcurrentDictionary<string, Tuple<ADGroup, DateTime>>(StringComparer.OrdinalIgnoreCase);
cacheCleanNext = DateTime.Now.AddMinutes(CacheCleanIntervalMinutes);
}