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        public delegate void SignMessage( string message );
 
#pragma warning disable CS8632 
        public event SignMessage? Notify;
#pragma warning restore CS8632
 
        // .....
        // .....
 
        // Метод входа
        public void LogIn( string name, string password )
        {
            bool b = false;
            if ( !_authsrv.IsAuthenticated )
                b = _authsrv.SignIn( name, password );
            Notify?.Invoke( $"{name} logged in {b}." );
        }
 
        // Метод выхода
        public void LogOut()
        {
            string cname = _authsrv.CurrentUser.Name;
            _authsrv.SignOut();
            Notify?.Invoke( $"{cname} logout completed." );
        }

        UManager mng = new();
        mng.Notify += PrintMessage;
 
        static void PrintMessage( string message ) => Console.WriteLine( message );
 
 
            mng.LogIn( "_Admin", "" );
 
            Console.WriteLine( $"{mng.AddUserRange( users )} users added"  );
 
            mng.LogOut();

public enum AuthorizationState
{
    Uknown,
    Authorized,
    Unauthorized,
}

public delegate void UserAuthorizationEventArgs(object sender, AuthorizationState newState);

public class UserAuthorizationService
{
    public AuthorizationState CurrentState { get; private set }
    public event AuthorizationEventArgs AuthorizationStateChanged;
 
    protected void RaiseActionAuthorizationState(AuthorizationState newState)
    {
        if(newState == CurrentState)
            return;
 
        CurrentState = newState;
        AuthorizationStateChanged?.Invoke(this, newState);
    }
 
    public virtual Login(LoginInfo loginInfo)
    {
          throw new NotImplementerException();
    }
 
    public virtual Logout()
    {
          throw new NotImplementerException();
    }
}

public class Program
{
    private static AuthorizationService service { get; } = new AuthorizationService();
    static Program()
    {
        service.AuthorizationStateChanged += OnAuthorizationStateChanged;
    } 
 
    private void OnAuthorizationStateChanged(object sender, AuthorizationState newState)
    {
        Console.WriteLine(newState == AuthorizationState.Authorized ? "User authorized" : "User deauthorized");
    }
 
   void Main()
    {
 
    }
}

throw new NotImplementerException();