// C# Extension Method

// Doc: https://csharp-extension.com/en/method/1002610/stringbuilder-extractstringarobassinglequote

​

// @nuget: Z.ExtensionMethods

​

using System;

using System.Text;

public class Program

{

    public static void Main()

    {

        int endIndex;

​

        // C# Extension Method: StringBuilder - ExtractStringArobasSingleQuote

        Console.WriteLine(new StringBuilder(" ").ExtractStringArobasSingleQuote());

        Console.WriteLine(new StringBuilder("@'z'").ExtractStringArobasSingleQuote().ToString());

        Console.WriteLine(new StringBuilder("@@'z'z").ExtractStringArobasSingleQuote(1, out endIndex).ToString());

        Console.WriteLine(endIndex);

    }

}