Reflect value of []byte

How do I retrieve the []byte value of this interface?

package main

import (
    "reflect"
)

func byteInterface() interface{} {
    return []byte("foo")
}

func main() {
    //var b []byte
    i := byteInterface()

    switch {
    case reflect.TypeOf(i).Kind() == reflect.Slice && (reflect.TypeOf(i) == reflect.TypeOf([]byte(nil))):

    default:
        panic("should have bytes")
    }
}