Empty property removed when serializing

[desmarest]

Describe the bug
Empty properties are removed when serializing.

Repro steps

            var openApiDocument = new OpenApiDocument
            {
                Components = new OpenApiComponents
                {
                    Schemas = new Dictionary<string, OpenApiSchema>
                    {
                        ["Object"] = new OpenApiSchema
                        {
                            Type = "object",
                            Properties = new Dictionary<string, OpenApiSchema>()
                        }
                    }
                }
            };

            var test = JObject.Parse(openApiDocument.SerializeAsJson(OpenApiSpecVersion.OpenApi2_0));
            Console.WriteLine(test);

Expected result

{
  "swagger": "2.0",
  "info": {},
  "paths": {},
  "definitions": {
    "Object": {
      "type": "object"
      "properties": {}
    }
  }
}

Actual result

{
  "swagger": "2.0",
  "info": {},
  "paths": {},
  "definitions": {
    "Object": {
      "type": "object"
    }
  }
}

[RachitMalik12]

@darrelmiller do you have any thoughts?

[darrelmiller]

There is no semantic difference between the two, so I'm not sure why for the "properties" property it matters. For properties where an empty object is semantically significant, like an empty paths object, we do keep the property. However, in this case we don't. It would be good to understand what is the concern here.