cache.go
func (c *cache) ItemCount() int {
	c.mu.RLock()
	n := len(c.items)
	c.mu.RUnlock()
	return n
}
func (c *cache) ItemCount() int {
	c.mu.RLock()
	n := len(c.items)
	c.mu.RUnlock()
	return n
}
func ( c * cache ) ItemCount ( ) int { c . mu . RLock ( ) n := len ( c . items ) c . mu . RUnlock ( ) return n }
// Returns the number of items in the cache. This may include items that have
// expired, but have not yet been cleaned up.
Returns the number of items in the cache . This may include items that have expired but have not yet been cleaned up .