need tests

PhoneBook.java

@@ -1,7 +1,48 @@
  
-
+import java.util.*;
 /**
  * Created by leon on 1/23/18.
  */
 public class PhoneBook {
+    private Map<String, ArrayList<String>> phoneBook;
+    
+    public PhoneBook() {
+        phoneBook = new TreeMap<String, ArrayList<String>>();
+    }
+    
+    public ArrayList<String> add(String name, String number) {
+        if (phoneBook.get(name) == null) {
+            phoneBook.put(name, new ArrayList<String>());
+        }
+        phoneBook.get(name).add(number);
+        
+        return phoneBook.get(name);
+    }
+    
+    public ArrayList<String> lookup(String name) {
+        return phoneBook.get(name);
+    }
+    
+    public String reverseLookup(String phoneNumber) {
+        String name = "not found";
+        for (Map.Entry<String, ArrayList<String>> entry : phoneBook.entrySet()) {
+            for (String numbers : entry.getValue()) {
+                if (numbers.equals(phoneNumber)) name = entry.getKey();
+            }
+        }
+        return name;
+    }
+    
+    public String display() {
+        StringBuilder phoneNumbers = new StringBuilder();
+        for (Map.Entry<String, ArrayList<String>> entry : phoneBook.entrySet()) {
+            phoneNumbers.append(entry.getKey() + " ");
+            for (String number : entry.getValue()) {
+                phoneNumbers.append(number + " ");
+            }
+            phoneNumbers.append("\n");
+        }
+        return phoneNumbers.toString();
+    }
+    
 }

PhoneBookTest.java

@@ -30,13 +30,10 @@ public class PhoneBookTest
     {
     }
 
-    /**
-     * Tears down the test fixture.
-     *
-     * Called after every test case method.
-     */
-    @After
-    public void tearDown()
-    {
+    @Test
+    public void addTest() {
+        PhoneBook phone = new PhoneBook();
+        phone.add("John", "215-658-1490");
+        assertEquals("215-658-1490", phone.lookup("John"));
     }
 }