randomized selection in C#

RSelect.cs

using System;
using System.Collections.Generic;

public class RSelect<T> where T : IComparable {
    private Random rnd = new Random();
    
    public T Select(IList<T> collection, int left, int right, int k) {
        if((right - left) <= 1)
            return collection[right];    
        
        int pivotIndex = this.Partition(collection, left, right, rnd.Next(left, right + 1));

        if(k > pivotIndex)
            return this.Select(collection, pivotIndex, right, k);
        else if(k < pivotIndex)
            return this.Select(collection, left, pivotIndex - 1, k);

        return collection[k];
    }

    private int Partition(IList<T> collection, int left, int right, int pivotIndex) {
        T pivot = collection[right];

        Swap(collection, right, pivotIndex);
        pivotIndex = left;

        for (int i = left; i < right; i++) {
            if(collection[i].CompareTo(pivot) < 0){
                Swap(collection, i, pivotIndex);
                pivotIndex++;
            }
        }

        collection[right] = collection[pivotIndex];
        collection[pivotIndex] = pivot;

        return pivotIndex;
    }

    private static void Swap(IList<T> collection, int first, int second) {
        T temp = collection[first];
        collection[first] = collection[second];
        collection[second] = temp;
    }
}