using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        IEmployee employee = new Employee();

        employee.Add(1);

    }

}

​

public class Employee : IEmployee{

    public List<int> Jobs {get { return new List<int>(); } }

}

​

public class IEmployee {

    IEnumerable<int> Jobs{get;}

}