How do I clear a System.Runtime.Caching.MemoryCache

I was struggling with this at first. MemoryCache.Default.Trim(100) does not work (as discussed). Trim is a best attempt, so if there are 100 items in the cache, and you call Trim(100) it will remove the ones least used.

Trim returns the count of items removed, and most people expect that to remove all items.

This code removes all items from MemoryCache for me in my xUnit tests with MemoryCache.Default. MemoryCache.Default is the default Region.

foreach (var element in MemoryCache.Default)
{
    MemoryCache.Default.Remove(element.Key);
}