CookieContainer.Add Method (CookieCollection)
Assembly: System (in System.dll)
If the Count property equals the Capacity property, one or more Cookie instances are removed from the container before adding the contents of the cookies parameter. Enough Cookie instances are removed to make room for cookies as follows: if there are expired instances, they are cleaned up. If not, or if more room is needed, then the least recently used CookieCollection is found and removed from the container.