using System; interface IField { void Accept(IFieldVisitor visitor); string GetLabel(); void SetLabel(string label); // other field properties/methods } class TextField : IField { private string label; public void Accept(IFieldVisitor visitor) { visitor.VisitTextField(this); } public string GetLabel() { return label; } public void SetLabel(string newLabel) { label = newLabel; } // other TextField properties/methods } interface IFieldVisitor { void VisitTextField(TextField field); void VisitRadioButton(RadioButton field); void VisitCheckbox(Checkbox field); // other field visitor methods } class FormVisitor : IFieldVisitor { public void VisitTextField(TextField field) { Console.WriteLine($"Text field '{field.GetLabel()}' visited."); } public void VisitRadioButton(RadioButton field) { /* implementation */ } public void VisitCheckbox(Checkbox field) { /* implementation */ } // other IFieldVisitor methods } // usage example var textField = new TextField() { Label = "Name:" }; var visitor = new FormVisitor(); textField.Accept(visitor); // outputs "Text field 'Name:' visited."The package/library used in this example is just the standard .NET library. No additional packages or libraries are required for this implementation.