using System;

using System.Threading.Tasks;

using System.Linq;

using System.Collections.Generic;

public class Program

{

    public void Main(){

        Func<bool,bool> f = i => {SomeAction();return true;};

        Console.WriteLine(SomeMethod(f));

    }

    public T SomeMethod<T>( Func<T, T> f ) 

    {

        return f(default(T));

    }

    public void SomeAction()

    {

        Console.WriteLine("called");

    }

}

​