AlamofireDecodable+Login.swift

import Alamofire    
...
  func login() {
        let urlStr = "\(serverUrl)\(EndpointTails.login.rawValue)"
        AF.request(urlStr, method: .get).responseDecodable { (response: DataResponse<PanpaResponse<User>, AFError>) in
            if let panpaResponse = response.value {
                switch panpaResponse.status {
                case .success:
                    guard let user: User = panpaResponse.data else { return }
                    print(user.username)
                case .failed:
                    print("API error with message: \(panpaResponse.message)")
                }
            } else {
                let errorResponse = PanpaResponse<User>()
                print("API error with message: \(errorResponse.message)")
            }
        }
    }