import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;

/**
* Write a description of class SpellChecker here.
*
* @author (your name)
* @version (a version number or a date)
*/
public class SpellChecker
{
private ArrayList<String> words;
private DictReader reader;
/**
* Constructor for objects of class SpellChecker
*/
public SpellChecker()
{
   reader = new DictReader("words.txt");
   words = reader.getDictionary();
}

/**
* This method returns the number of words in the dictionary.
*
*/
public int numberOfWords()
{
   return words.size();
}

/**
* This method returns true, if (and only if) the given word is found in the dictionary.
*
*/
public boolean isKnownWord(String word)
{
   boolean result = false;
   for(String w: words) {
         if(w.equalsIgnoreCase(word)) {
            result = true;
            break;
         }
   }
   return result;
}

/**
* This method returns true if (and only if) all words in the given wordList are found in the dictionary.
*/
public boolean allKnown(ArrayList<String> wordList)
{
   boolean result = true;
   for (String w: wordList) {
      if(!isKnownWord(w)) {
            result = false;
            break;
      }
   }
   return true;
}

/**
* This method tests the allKnown method. You do not need to change this method.
*/
public boolean testAllKnown()
{
   ArrayList<String> testWords = new ArrayList<String>();
   testWords.add("Abu");
   testWords.add("Chou");
   if(allKnown(testWords))
   {
         return true;
   }
   else
   {
         return false

• You will need a TwoThreeTree class, with a TwoThreeTree construct...