Java Collections .unmodifiableSortedSet ( SortedSet <T> s)

public static <T> SortedSet <T> unmodifiableSortedSet(SortedSet <T> s)

import java.util.Collections;
import java.util.Set;
import java.util.SortedSet;
import java.util.TreeSet;
/*  w  w  w. j a  v  a 2 s.  co m*/
public class Main {
   public static void main(String[] s) {
      SortedSet<String>  set = new TreeSet<String> ();
      
      set.add("Welcome");
      set.add("to");
      set.add("java2s.com");
      
      System.out.println("Initial set value: "+set);
      
      // create unmodifiable sorted set
      Set<String> unmodsortset = Collections.unmodifiableSortedSet(set);

      // try to modify the sorted set
      unmodsortset.add("Hello");
   }
}