//: holding/SetOfInteger.java
import java.util.*;

public class SetOfInteger {
  public static void main(String[] args) {
    Random rand = new Random(47);
    Set<Integer> intset = new HashSet<>();
    for(int i = 0; i < 10000; i++)
      intset.add(rand.nextInt(30));
    System.out.println(intset);
  }
} /* Output:
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17, 16, 19, 18, 21, 20, 23, 22, 25, 24, 27, 26, 29, 28]
*///:~