Gets or sets an optional delegate that is called after the check for expired items is made.

Gets or sets an optional delegate that is called before the check is made for expired items.

Gets the current count of items in the list.

Gets or sets an optional delegate that is called when the count changes. The new count is passed to the delegate. The list is locked to the calling thread while the delegate is running. The delegate will occasionally be called on a background thread.

Gets or sets the minimum number of milliseconds that an item can remain within the list.

Gets or sets the minimum number of milliseconds to wait between checks for expiring items.