Check if a HashSet is a subset of the specified collection in CSharp

using System;//from   w  w w.  j a v  a  2s  . c  o  m
using System.Collections.Generic;
public class MainClass{
  public static void Main(String[] argv){  
    HashSet<int> lowNumbers = new HashSet<int>();
    HashSet<int> allNumbers = new HashSet<int>();

    for (int i = 1; i < 5; i++)
    {
        lowNumbers.Add(i);
    }

    for (int i = 0; i < 10; i++)
    {
        allNumbers.Add(i);
    }

    Console.WriteLine(lowNumbers.IsSubsetOf(allNumbers));

  }
}