What are Callable classes?

To allow an instance of your Dart class to be called like a function.

Implement the call() method.

class ResponseObject {
  call(String function, String status, dynamic data) {
    return [function, status, data];
  }
}

main() {
  var response = new ResponseObject();
  var data = {'Rock', 'Star'};
  var result = response('Person', 'FETCHED SUCCESSFULLY', data);

  print(result);
}