Joining 2 structs from mongodb

I have a function that retrieve the mongodb admin users using .command

In the below function, I have the DbUsers struct, and I am running the command to retrieve the users from 2 different database.

My question is, how can I concat the 2 results (adminUsers & externalUsers) and return after merged? They are of the same struct.

type DbUsers struct {
    ...lots of stuff about the server
    Users []Users 
}

type Users struct {
   User string
   ...lots of stuff
}

func getUsers() Users {
    admin := CNX.Database("admin")
    external := CNX.Database("$external")

    command := bson.D{primitive.E{Key: "usersInfo", Value: 1}}

    var adminUsers DbUsers
    var externalUsers DbUsers
    err := admin.RunCommand(context.TODO(), command).Decode(&adminUsers)
    if err != nil {
        panic(err)
    }

    err2 := external.RunCommand(context.TODO(), command).Decode(&externalUsers)
    if err2 != nil {
        panic(err2)
    }

    //New to Golang, not sure what I am doing but this doesn't work


    return []Users{adminUsers.Users, externalUsers.Users}
}

>Solution :

You can do

return append(adminUsers.Users, externalUsers.Users...)