How do I remove duplicate values from slice with Go Lang

func removeDuplicates(numbers []int) []int {
// create a slice to store the result of removed duplicates
var result []int = []int{}

// create a map to store key value pairs
var removed map[int]int = map[int]int{}

// insert key value pairs into map
for _, number := range numbers {
removed[number] = number
}

// get all keys from map
for key := range removed {
result = append(result, key)
}

// return the result
return result
}

package main

import (
"fmt"
)

func main() {
  var numbers []int = []int{5, 6, 1, 9, 1, 3, 7, 3, 9, 7, 6, 4, 3, 2, 9, 9, 9}

  var result []int = removeDuplicates(numbers)

  fmt.Println("The result: ", result)
}

func removeDuplicates(numbers []int) []int {
var result []int = []int{}

var removed map[int]int = map[int]int{}

for _, number := range numbers {
removed[number] = number
}

for key := range removed {
result = append(result, key)
}

return result
}