実行時に名前 (文字列) を使用して Go 関数を呼び出すにはどうすればよいですか?

package main

import "fmt"

func someFunction1(a, b int) int {
    return a + b
}

func someFunction2(a, b int) int {
    return a - b
}

func someOtherFunction(a, b int, f func(int, int) int) int {
    return f(a, b)
}

func main() {
    fmt.Println(someOtherFunction(111, 12, someFunction1))
    fmt.Println(someOtherFunction(111, 12, someFunction2))
}

123
99

m := map[string]func(int, int) int{
    "someFunction1": someFunction1,
    "someFunction2": someFunction2,
}

...

z := someOtherFunction(x, y, m[key])