What's the difference of time duration between persist and cache?

Hi there
  There are two time duration of gin-cache: persist.NewMemoryStore(), cache.CacheByRequestURI, what's the difference between them?
  Can they merge into one time duration?


```	
memoryStore := persist.NewMemoryStore(1 * time.Minute)
	app.GET("/hello",
		cache.CacheByRequestURI(memoryStore, 2*time.Second),
		func(c *gin.Context) {
			c.String(200, "hello world")
		},
	)
```