fixed test

PhoneBook.java

 public class PhoneBook {
     String name;
     String phoneNumber;
+    
+    // create treemap(hashmap), has key String, value arrayList of Strings
     TreeMap<String, ArrayList<String>> phoneBook = new TreeMap<>();
-
+    
+    // construct an instance of phoneBook
     public PhoneBook(TreeMap<String, ArrayList<String>> phoneBook) {
         this.phoneBook = phoneBook;
     }
-
+    
+    // default constructor
     public PhoneBook(){}
 
     public void add(String name, String phoneNumber){
+        // if phonebook does NOT contain key(name), put name on list
         if (!phoneBook.containsKey(name)) {
             ArrayList<String> list = new ArrayList<>();
             list.add(phoneNumber);
-            phoneBook.put(name, list);          
+            phoneBook.put(name, list);
+            // or else, create tempoary arraylist and add phonenumber
         } else {
-
             ArrayList<String> temp = phoneBook.get(name);
             temp.add(phoneNumber);
-            phoneBook.replace(name, phoneBook.get(name), temp);//key,old,new
-
+            
+            //(key,old key,new key)
+            phoneBook.replace(name, phoneBook.get(name), temp);
         }   
     }
 
     public void remove(String name, String phoneNumber){
+        
         ArrayList<String> list = phoneBook.get(name);
-
+        // if only one number, remove name
         if(list.size() == 1) {
-            phoneBook.remove(name); 
+            phoneBook.remove(name);
+            
+            // or else create temp arraylist and remove phonenumber/replace
+            // in list with parameters (name, list, temp)
         } else {
             ArrayList<String> temp = phoneBook.get(name);
             temp.remove(phoneNumber);
     public void removeRecord(String name) {
         phoneBook.remove(name);
     }
-
+    
+    // lookup returns list of phonenumbers for given name
     public ArrayList<String> lookup(String name){
         return phoneBook.get(name);
     }
-
+    
+    
     public String reverseLookup(String phoneNumber) {
-        // for each entry in phonebook
+        // for each entry in phonebook, lookup array of name/number
         for (Map.Entry<String, ArrayList<String>> entry : phoneBook.entrySet()) {
             // gets name
             String name = entry.getKey();
         // build a string to display
         StringBuilder sb = new StringBuilder();
         
+        // For (string, phone number) entry, iterate thru phoneBook.entrySet
         for (Map.Entry<String, ArrayList<String>> entry : phoneBook.entrySet()){
             
             String name = entry.getKey();
             ArrayList<String> numbers = entry.getValue();
-
+            
+            // when key got, add name to space " "
             sb.append(name).append(" ");
 
             // for each number in element, append to name

pets

-private PetOwner petOwner;