title: There is a way to know which type json is represent?
body: <p>let's say i have two objects: Person and ReqSingUp, and ReqSingUp contains Person.</p>
  
  <p>Now if i try:</p>
  
  <pre><code>Person p=new Person("dan","lala");
  ReqSingUp reqSingUp=new ReqSingUp(p);
  String s = gson.toJson(reqSingUp,ReqSingUp.class);
  Object o = gson.fromJson(s, Object.class);
  
  if (o instanceof ReqSingUp) {
      System.out.println("it's ReqSingUp");
  }
  if (o instanceof Person ) {
      System.out.println("it's person");
  }
  </code></pre>
  
  <p>it does not satisfy any condition (not <code>instanceof ReqSingUp</code> and not <code>instanceof Person</code>  ).</p>
  
  <p>Is there a way to know which type it is?</p>
  
  <p>Thanks in advance.</p>