I have a class with multiple properties. One property containes properly formed JSON. 
Something like:
public MyClass {
    public string Val {get;set;}
    public string AlreadyJson {get;set;} // properly formed JSON
}
Now I need to send this object to some external api using PostAsync. To do this I have to serialize MyClass object to JSON first. 
However, as AlreadyJSON property is already serialized (it is already json), I need to ignore it (by ignore I mean - I still have to include it into resulting json, but I do not need to serialize it).
The same should apply to deserialization. I believe it should be easy with some attribute to MyClass, but unfourtunately I could not achieve this. For instance, adding JsonIgnore would simple ignore property and would not include it into resulting string.
Any solution would be good: using Newtonsoft or using built in DataContractJsonSerializer