code: func NewLRUNoTS(size int) Cache {
  	if size < 1 {
  		panic("invalid cache size")
  	}
  
  	return &LRUNoTS{
  		list:  list.New(),
  		cache: NewMemoryNoTS(),
  		size:  size,
  	}
  }
docs: // NewLRUNoTS creates a new LRU cache struct for further cache operations. Size
  // is used for limiting the upper bound of the cache