[ROS2] calling method in Node class

edit

Hi, I would like to create a node class that keeps calling a Service.

class GetObject : public rclcpp::Node
{
public:

  GetObject() : Node("main")
  {
    auto getobj = this->create_client<canopen_msgs::srv::GetObject>("/get_object");  
  }
  void Get()
  {
     // code that calls the Service
  }
}

What is the correct way of calling the Get() method ? I would like to have following structure:

int main(int argc, char *argv[])

{
    rclcpp::init(argc, argv);
    auto GetConstructor = std::make_shared<GetObject>();

    while (rclcpp::ok())
    {
        // call the Get() method

    }

    return 0;

}

Thanks !