创建一个简单的Json响应GO

I'm looking at a tutorial for creating REST API's with GO. I'm trying to build a web server and serve up a simple json response:

package main

import(
    "encoding/json"
    "fmt"
    "net/http"
)

type Payload struct {
    Stuff Data
}

type Data struct {
    Fruit Fruits
    Veggies Vegetables
}

type Fruits map[string]int
type Vegetables map[string]int

func serveRest(w http.ResponseWriter, r *http.Request) {
    response, err := getJsonResponse()
    if err != nil {
        panic(err)
    }

    fmt.Fprintf(w, string(response))
}

func main() {
    http.HandleFunc("/", serveRest)
    http.ListenAndServe("localhost:7200", nil)
}

func getJsonResponse() ([]byte, error){
    fruits := make(map[string]int)
    fruits["Apples"] = 25
    fruits["Oranges"] = 11

    vegetables := make(map[string]int)
    vegetables["Carrots"] = 21
    vegetables["Peppers"] = 0

    d := Data(fruits, vegetables)
    p := Payload(d)

    return json.MarshalIndent(p, "", "  ") 
}

When I run this code I get the error:

too many arguments to conversion to Data: Data(fruits, vegetables)

I don't understand why its throwing that error since its expecting 2 arguments and I'm passing in 2 arguments. This is my first day trying GO so maybe I'm missing some concept or something.

I found my error I passed in a function instead of an object to the types I created:

d := Data(fruits, vegetables)
p := Payload(d)

should be:

d := Data{fruits, vegetables}
p := Payload{d}