In GWT, how can I serialize/unserialize a Place using JSON in its tokenizer?

I would like to create a standard Tokenizer for my places in GWT.

To do so, I would like to use the json format. Something like this :

public String getToken(T place) {
   return transformToJSON(place);
 }
 
 public T getPlace(String token) {
   return (T)transformJSONToObject(token);
 }
 

I can't find a way to implements transformToJSON and transformJSONToObject. I've tried to use the JSONParser of GWT but it's quite limited to JavascriptObject (and Places are not JavascriptObject).

How can I achieve it ?

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