code: func (c *LRU) Purge() {
  	for k, v := range c.items {
  		if c.onEvict != nil {
  			c.onEvict(k, v.Value.(*entry).value)
  		}
  		delete(c.items, k)
  	}
  	c.evictList.Init()
  }
docs: // Purge is used to completely clear the cache.