用Go语言帮我写一个LRU缓存，可以设置过期时间

好的，我可以帮您写一个Go语言的LRU缓存，以下是示例代码：

package main

import (
    "container/list"
    "fmt"
    "time"
)

type CacheItem struct {
    key        string
    value      interface{}
    expired_at time.Time
}

type LRUCache struct {
    capacity int
    items    map[string]*list.Element
    list     *list.List
}

func NewLRUCache(capacity int) *LRUCache {
    return &LRUCache{
        capacity: capacity,
        items:    make(map[string]*list.Element),
        list:     list.New(),
    }
}

func (c *LRUCache) Get(key string) (interface{}, bool) {
    if elem, ok := c.items[key]; ok {
        item := elem.Value.(*CacheItem)
        if item.expired_at.IsZero() || item.expired_at.After(time.Now()) {
            c.list.MoveToFront(elem)
            return item.value, true
        } else {
            c.list.Remove(elem)
            delete(c.items, key)
        }
    }
    return nil, false
}

func (c *LRUCache) Set(key string, value interface{}, expired time.Duration) {
    if elem, ok := c.items[key]; ok {
        c.list.MoveToFront(elem)
        elem.Value.(*CacheItem).value = value
        elem.Value.(*CacheItem).expired_at = time.Now().Add(expired)
    } else {
        if len(c.items) >= c.capacity {
            tail := c.list.Back()
            if tail != nil {
                delete(c.items, tail.Value.(*CacheItem).key)
                c.list.Remove(tail)
            }
        }
        elem := c.list.PushFront(&CacheItem{key, value, time.Now().Add(expired)})
        c.items[key] = elem
    }
}

func main() {
    cache := NewLRUCache(2)
    cache.Set("key1", "value1", time.Second*5)
    cache.Set("key2", "value2", time.Second*10)
    cache.Set("key3", "value3", time.Second*15)

    if value, ok := cache.Get("key1"); ok {
        fmt.Println("key1:", value)
    } else {
        fmt.Println("key1 not found")
    }

    if value, ok := cache.Get("key2"); ok {
        fmt.Println("key2:", value)
    } else {
        fmt.Println("key2 not found")
    }

    if value, ok := cache.Get("key3"); ok {
        fmt.Println("key3:", value)
    } else {
        fmt.Println("key3 not found")
    }
}

这个LRU缓存可以设置过期时间，当缓存中的数据过期时，会自动删除。