Environment version: .NET 9.0.0 (9.0.0), Unix 6.8.0.1014
Newtonsoft.Json version: Newtonsoft.Json, Version=13.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed

Re-serialized MyApiResponseClass:
{
  "custom_attributes": [
    {
      "attribute_code": "required_options",
      "value": "simple"
    },
    {
      "attribute_code": "category_ids",
      "value": [
        "2"
      ]
    },
    {
      "attribute_code": "has_options",
      "value": "0"
    },
    {
      "attribute_code": "an_object",
      "value": {
        "0": "1"
      }
    }
  ]
}