问“AuthDataResult”类型的值没有成员“isEmailVerification”

EN

func signIn(email:String?, password:String?) {
    if email == nil || password == nil {
        showAlert(title: "Login Error!", message: "All fields are required.")
    } else {
        SwiftLoader.show(animated: true)

        Auth.auth().signIn(withEmail: email!, password: password!) { (user, error) in
            SwiftLoader.hide()

            if let err = error {
                self.showAlert(title: "Login Error!", message: err.localizedDescription)
            } else  {
                if (user?.isEmailVerification){ //error:"Value of type 'AuthDataResult' has no member 'isEmailVerification'"
                    self.sendEmailVerification()
                }else{
                    self.showAlert(title: "", message: "Has iniciado sesión correctamente")
                }
            }
        }
    }
}