example.cs

public interface IEmployee
{
    void Work();
}

public class Human : IEmployee
{
    public void Work()
    {
        // ....working
    }
}

public class Robot : IEmployee
{
    public void Work()
    {
        //.... working much more
    }
}

public class Manager
{
    private readonly IEnumerable<IEmployee> _employees;

    public Manager(IEnumerable<IEmployee> employees)
    {
        _employees = employees;
    }

    public void Manage()
    {
        foreach (var employee in _employees)
        {
            _employee.Work();
        }
    }
}