unwrapping an Optional value
问题 I am trying to login with macbook using code but I keep on getting this error: Thread 1: Fatal error: Unexpectedly found nil while unwrapping an Optional value // API to log an user in func login(userType: String, completionHandler: @escaping (NSError?) -> Void) { let path = "api/social/convert-token/" let url = baseURL!.appendingPathComponent(path) let params: [String: Any] = [ "grant_type": "convert_token", "client_id": CLIENT_ID, "client_secret": CLIENT_SECRET, "backend": "facebook",