Handle the action

handleAction.swift

class NotificationViewController: UIViewController, UINotificationContentExtension
{
    func didReceive(_ response: UNNotificationResponse,
        completionHandler done: (UNNotificationContentExtensionResponseOption) -> Void)
    {
        server.postEventResponse(response.actionIdentifier) 
        {
            if response.actionIdentifier == "accept"
            {
                eventResponse.text = "Going!"
                eventResponse.textColor = UIColor.green()
            } 
            else if response.actionIdentifier == "decline"
            {
                eventResponse.text = "Not going :("
                eventResponse.textColor = UIColor.red()
            }
            done(.dismiss)
        }
    } 
}

Hi,
I am trying to implement something like this in my app, I have a question regarding the line no.6, Where did you get/create the object server.