// C# Extension Method

// Doc: [url will be determined later]

​

// @nuget: Z.ExtensionMethods

​

using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        var list = new List<string> {"FizzExisting"};

​

        // C# Extension Method: ICollection<T> - AddRangeIf

        list.AddRangeIf(x => !list.Contains(x), "Fizz"); // Add "Fizz" value

        list.AddRangeIf(x => !list.Contains(x), "FizzExisting", "Buzz"); // Add "Buzz" value but doesn't add "FizzExisting"

​

        foreach (var item in list)

        {

            Console.WriteLine(item);

        }

    }

}