Concrete Command (AddTextCommand):?

• The AddTextCommand is a concrete implementation of the ICommand

interface. It encapsulates the request to add text to the document.

• The Execute() method adds the specified text to the document, and the

Undo() method removes that text.

public class AddTextCommand : ICommand
{
private readonly Document _document;
private readonly string _text;
public AddTextCommand(Document document, string text)
{
_document = document;
_text = text;
}
public void Execute() => _document.AddText(_text);
public void Undo() => _document.RemoveText(_text);
}