Converting Dataset to Json with Empty datatable's columns

Question

Hi everyone, I want to convert DataSet to Json using newtonsoft. I converted it successfully but an issue here is the datatable with 0 rows are column less in json.

 

I'm getting the json like below, but I want to have dt_3 with its columns names.

 

What I'm doing is 

string json_withoutStoreDetails = JsonConvert.SerializeObject(dset, Newtonsoft.Json.Formatting.Indented);

{
  "dt_1": [
    {
      "depid": 51.0,
      "DepName": "Honda",
      "Amount": 110.50
    },
    {
      "depid": 54.0,
      "DepName": "Toyota",
      "Amount": 100.60
    },
    {
      "depid": 56.0,
      "DepName": "Diahatsu",
      "Amount": 120.00
    },
    {
      "depid": 57.0,
      "DepName": "Bedford",
      "Amount": 380.00
    },
  ],
  "dt_2": [
    {
      "depid": 50,
      "DepName": "AlloyRims",
      "Amount": 21.50
    }
  ],
  "dt_3": [

  ],
}