You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: 1028. Recover a Tree From Preorder Traversal_test.go
    path of file: ./repos/LeetCode-Go/leetcode/1028.Recover-a-Tree-From-Preorder-Traversal
    
    the code of the file until where you have to start completion: package leetcode

import (
	"fmt"
	"testing"

	"github.com/hal
    
func Test_Problem1028(t *testing.T) {

	qs := []question1028{
		{
			para1028{"1-2--3--4-5--6--7"},
			ans1028{[]int{1, 2, 5, 3, 4, 6, 7}},
		},

		{
			para1028{"1-2--3---4-5--6---7"},
			ans1028{[]int{1, 2, 5, 3, structures.NULL, 6, structures.NULL, 4, structures.NULL, 7}},
		},

		{
			para1028{"1-401--349---90--88"},
			ans1028{[]int{1, 401, structures.NULL, 349, 88, 90}},
		},
	}

	fmt.Printf("------------------------Leetcode Problem 1028------------------------\n")

	for _, q := range qs {
		_, p := q.ans1028, q.para1028
		fmt.Printf("【input】:%v       【output】:%v\n", p, structures.Tree2ints(recoverFromPreorder(p.one)))
	}
	fmt.Printf("\n\n\n")
}