title: How to pass a list of json to body of http request (post) in Flutter?
body: <p>I have objects that will filled by a user in a form. I parse these objects to json and add that json in a list to pass in body of request. But i cant do this. </p>
  
  <pre><code>  incrementListPaymentSlipes(PaymentSlipes objPayment) async {
      objPayment.name = "Douglas";
      objPayment.personalId = "00000000000";
      Map&lt;String, dynamic&gt; json = objPayment.toJson();
      listPaymentSlipes.add(jsonEncode(json));
    }
  </code></pre>
  
  <pre><code>var response = await http.post(url, body: {
  "payment_slips": listPaymentSlipes,
  }
  </code></pre>
  
  <p>example of correct body:</p>
  
  <pre><code>"payment_slips": [
      {      
        "personal_id": "01888728680",
        "name": "Fulano da Silva"
      }
    ]
  </code></pre>
  
  <pre><code> {"error":"'{{personal_id: 00000000000, name: Douglas}}' Ã© invalido como 'payment_slips'","code":"payment_slips_invalid"}```
  </code></pre>