Tries to create an instance of specified class with using different approaches
1) instantiate via default contructor
2) if failed, check iterate through all declared constructor and tries to instantiate with null args
3) if failed throws exception
Set of convinient methods to access data from JSON structure
String email = JS.from(jsonString).at("user").getString("email");
//
String expiresAt = JS.from(jsonString).at("user").at("tokens").at(i).getString("expires_at");