code: func (c *BufferLRU) Get(key int64) ([]byte, bool) {
  	c.mut.Lock()
  	defer c.mut.Unlock()
  
  	ee, ok := c.cache[key]
  	if !ok {
  		return nil, false
  	}
  
  	c.ll.MoveToFront(ee)
  	return ee.Value.(buffer).Slice, true
  }
docs: // Get returns a buffer by its key. It marks the buffer as used. If the buffer
  // is not in the cache, (nil, false) will be returned.