using System;

public class Program

{

    public static void Main()

    {

        A aobj = new A();

        aobj.PrintConsole();

        B.PrintConsole();

    }

} 

​

public class A

{

}

​

​

public static class B

{

    public static void PrintConsole(this A a) =>

        Console.WriteLine("from extension method");

    public static void PrintConsole() => Console.WriteLine("method from class b");

}

​

​

​