How do I parallelize tests safely in benchmarks for Go?

package main

import (
    "fmt"
    "testing"
)

var results []int

func parallelFunction(n int, wg *sync.WaitGroup) {
    defer wg.Done()
    // Simulate some work
    result := n * n
    results = append(results, result)
}

func BenchmarkParallelTests(b *testing.B) {
    for i := 0; i < b.N; i++ {
        var wg sync.WaitGroup
        for j := 0; j < 10; j++ {
            wg.Add(1)
            go parallelFunction(j, &wg)
        }
        wg.Wait() // Wait for all goroutines to finish
    }
}

func main() {
    fmt.Println("Run `go test -bench=.` to see the benchmark results.")
}