Goroutine睡眠和代码死锁。怎么解决呢？

Question

http://play.golang.org/p/r92-KtQEGl我正在尝试执行此代码。它将引发死锁错误。我想念什么？package mainimport "tour/tree"import "fmt"// Walk walks the tree t sending all values// from the tree to the channel ch.func Walk(t *tree.Tree, ch chan int){    var temp chan int    ch <- t.Value    if t.Left!=nil{go Walk(t.Left,temp)}    if t.Right!=nil{go Walk(t.Right,temp)}    for i := range temp{        ch <- i    }    close(ch)}// Same determines whether the trees// t1 and t2 contain the same values.func Same(t1, t2 *tree.Tree) bool