Create an NUnit test on an infinite sequence

I have this method:

public static IEnumerable<T> Jumping<T>( this IEnumerable<T> sequence, int step)
{
    if(sequence==null)
        throw new ArgumentNullException();
    if(step<0)
        throw new ArgumentOutOfRangeException();
    var s = sequence.GetEnumerator();
    for (int i = 0; i <= step; i++)
    {
        if (!s.MoveNext())
        {
            s.Reset();
            s.MoveNext();
        }
        if (i == step)
        {
            i = 0;
            yield return s.Current;
        }
    }
}

The request is to create a NUnit test with an infinite sequence, how can I do it ?