Недоделка

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Reflection;
using System.Security.Cryptography.X509Certificates;

internal class Program
{
    static void Main(string[] args)
    {
        const string CommandExit = "Exit";
        const string CommandShowAllBooks = "1";
        const string CommandAddBook = "2";
        const string CommandRemoveBook = "3";
        const string CommandSearchBook = "4";

        bool isRun = true;

        Library library = new Library();

        while (isRun)
        {
            Console.Clear();
            Console.WriteLine($"{CommandShowAllBooks} - Показать все книги." +
                $"\n{CommandAddBook} - Добавить книгу." +
                $"\n{CommandRemoveBook} - Убрать книгу." +
                $"\n{CommandSearchBook} - Найти книгу." +
                $"\n{CommandExit} - Завершить программу.");

            switch (Console.ReadLine())
            {
                case CommandShowAllBooks:
                    library.ShowAllBooks();
                    break;

                case CommandAddBook:
                    library.AddBook();
                    break;

                case CommandRemoveBook:
                    library.RemoveBook();
                    break;

                case CommandSearchBook:
                    library.SearchBook();
                    break;

                case CommandExit:
                    isRun = false;
                    break;

                default:
                    Console.WriteLine("Ошибка ввода.");
                    break;
            }
        }

        Console.WriteLine("Программа завершена.");
        Console.ReadKey();
    }
}

class Book
{
    public Book(string name, string releaseDate, string author)
    {
        Name = name;
        ReleaseDate = releaseDate;
        Author = author;
    }

    public string Name { get; private set; }
    public string ReleaseDate { get; private set; }
    public string Author { get; private set; }

    public void ShowInfo()
    {
        Console.WriteLine($"Книга: {Name}. Автор: {Author}. Год издания: {ReleaseDate}.");
    }
}

class Library
{
    private List<Book> _books = new List<Book>();

    public Library()
    {
        _books.Add(new Book("", "", ""));
        _books.Add(new Book("", "", ""));
        _books.Add(new Book("", "", ""));
        _books.Add(new Book("", "", ""));
        _books.Add(new Book("", "", ""));
    }

    public void ShowAllBooks()
    {

    }

    public void AddBook()
    {

    }

    public void RemoveBook()
    {

    }

    public void SearchBook()
    {

    }
}