protected LazyPool(string label, int maxPoolSize, TimeSpan poolTimeout)
{
logger = LoggingProvider.GetLogger(GetType());
Label = label;
MaxPoolSize = maxPoolSize;
PoolTimeout = poolTimeout;
currentPoolSize = 0;
currentFreeCount = 0;
pool = new SemaphoreSlim(maxPoolSize, maxPoolSize);
bag = new ConcurrentBag <TResource>();
}