关于迭代器的一个有关问题

import java.util.*;public class SortedSetDemo {  //private static Test monitor = new Test();  public static void main(String[] args) {    SortedSet sortedSet = new TreeSet(Arrays.asList(    "one two three four five six seven eight".split(" ")));    System.out.println(sortedSet);    Object      low = sortedSet.first(),      high = sortedSet.last();    System.out.println(low);    System.out.println(high);    Iterator it = sortedSet.iterator();    for(int i = 0; i <= 6; i++) {       [b]  if(i == 3) low = it.next();            if(i == 6) high = it.next();         [/b]                   else it.next();    }    System.out.println(low);    System.out.println(high);    System.out.println(sortedSet.subSet(low, high));    System.out.println(sortedSet.headSet(high));    System.out.println(sortedSet.tailSet(low));    /*monitor.expect(new String[] {      "[eight, five, four, one, seven, six, three, two]",      "eight",      "two",      "one",      "two",      "[one, seven, six, three]",      "[eight, five, four, one, seven, six, three]",      "[one, seven, six, three, two]"    });*/  }} ///:~