diff --git a/build.gradle b/build.gradle
index e2728eb4..a9cb134a 100644
--- a/build.gradle
+++ b/build.gradle
@@ -294,6 +294,7 @@ project(':collections') {
 configure(subprojects - project(':onjava')) {
     dependencies {
         compile project(':onjava')
+        compile group: 'com.google.guava', name: 'guava', version: '19.0'
         compile "org.openjdk.jmh:jmh-core:${jmh.jmhVersion}"
         compile group: 'org.apache.logging.log4j', name: 'log4j-api', version: '2.6.2'
         compile group: 'org.apache.logging.log4j', name: 'log4j-core', version: '2.6.2'
diff --git a/verifying/GuavaPreconditions.java b/verifying/GuavaPreconditions.java
new file mode 100644
index 00000000..5dabcd21
--- /dev/null
+++ b/verifying/GuavaPreconditions.java
@@ -0,0 +1,14 @@
+// verifying/GuavaPreconditions.java
+// (c)2016 MindView LLC: see Copyright.txt
+// We make no guarantees that this code is fit for any purpose.
+// Visit http://mindviewinc.com/Books/OnJava/ for more book information.
+// Demonstrating Guava Preconditions
+import static com.google.common.base.Preconditions.*;
+
+public class GuavaPreconditions {
+
+  public static void main(String[] args) {
+  }
+}
+/* Output:
+*/
diff --git a/verifying/Queue.java b/verifying/Queue.java
index 6138dc44..cb7e2aae 100644
--- a/verifying/Queue.java
+++ b/verifying/Queue.java
@@ -97,7 +97,7 @@ public class Queue {
     private int i = 0;
     public WhiteBoxTest() {
       while(i < 5) // Preload with some data
-        queue.put("" + i++);
+        queue.put(Integer.toString(i++));
     }
     // Support methods:
     private void showFullness() {
@@ -118,7 +118,7 @@ public class Queue {
       System.out.println(queue.get());
       System.out.println(queue.get());
       while(!queue.full())
-        queue.put("" + i++);
+        queue.put(Integer.toString(i++));
       String msg = "";
       try {
         queue.put("");
@@ -160,7 +160,7 @@ public class Queue {
     public void circularity() {
       System.out.println("testCircularity");
       while(!queue.full())
-        queue.put("" + i++);
+        queue.put(Integer.toString(i++));
       showFullness();
       // White-box testing accesses private field:
       assertTrue(queue.wrapped);
@@ -168,7 +168,7 @@ public class Queue {
         System.out.println(queue.get());
       showEmptiness();
       while(!queue.full())
-        queue.put("" + i++);
+        queue.put(Integer.toString(i++));
       showFullness();
       while(!queue.empty())
         System.out.println(queue.get());
diff --git a/verifying/JUnitDemo.java b/verifying/SimpleJUnit.java
similarity index 69%
rename from verifying/JUnitDemo.java
rename to verifying/SimpleJUnit.java
index 59aa70bf..3dd52d63 100644
--- a/verifying/JUnitDemo.java
+++ b/verifying/SimpleJUnit.java
@@ -1,13 +1,11 @@
-// verifying/JUnitDemo.java
+// verifying/SimpleJUnit.java
 // (c)2016 MindView LLC: see Copyright.txt
 // We make no guarantees that this code is fit for any purpose.
 // Visit http://mindviewinc.com/Books/OnJava/ for more book information.
 // Simple use of JUnit to test ArrayList
 import java.util.*;
-import org.junit.Test;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
-import static java.lang.System.out;
+import org.junit.*;
+import static org.junit.Assert.*;
 
 // So we can see the list objects being created,
 // and keep track of when they are cleaned up:
@@ -15,33 +13,28 @@ class CountedList extends ArrayList<String> {
   private static int counter = 0;
   private int id = counter++;
   public CountedList() {
-    out.println("CountedList #" + id);
+    System.out.println("CountedList #" + id);
   }
   public int getId() { return id; }
 }
 
-public class JUnitDemo {
-  private CountedList list = new CountedList();
-  // You can use the constructor instead of setUp():
-  public JUnitDemo() {
+public class SimpleJUnit {
+  private CountedList list;
+  @Before
+  public void initialize() {
+    list = new CountedList();
+    System.out.println("Set up for " + list.getId());
     for(int i = 0; i < 3; i++)
-      list.add("" + i);
+      list.add(Integer.toString(i));
   }
-  // Thus, setUp() is optional, but is run right
-  // before the test:
-  protected void setUp() {
-    out.println("Set up for " + list.getId());
-  }
-  // tearDown() is also optional, and is called after
-  // each test. setUp() and tearDown() can be either
-  // protected or public:
-  public void tearDown() {
-    out.println("Tearing down " + list.getId());
+  @After
+  public void cleanup() {
+    System.out.println("Cleaning up " + list.getId());
   }
   // All tests are marked with the @Test annotation:
   @Test
   public void insert() {
-    out.println("Running testInsert()");
+    System.out.println("Running testInsert()");
     assertEquals(list.size(), 3);
     list.add(1, "Insert");
     assertEquals(list.size(), 4);
@@ -49,7 +42,7 @@ public class JUnitDemo {
   }
   @Test
   public void replace() {
-    out.println("Running testReplace()");
+    System.out.println("Running testReplace()");
     assertEquals(list.size(), 3);
     list.set(1, "Replace");
     assertEquals(list.size(), 3);
@@ -68,12 +61,12 @@ public class JUnitDemo {
   }
   @Test
   public void order() {
-    out.println("Running testOrder()");
+    System.out.println("Running testOrder()");
     compare(list, new String[] { "0", "1", "2" });
   }
   @Test
   public void remove() {
-    out.println("Running testRemove()");
+    System.out.println("Running testRemove()");
     assertEquals(list.size(), 3);
     list.remove(1);
     assertEquals(list.size(), 2);
@@ -81,7 +74,7 @@ public class JUnitDemo {
   }
   @Test
   public void addAll() {
-    out.println("Running testAddAll()");
+    System.out.println("Running testAddAll()");
     list.addAll(Arrays.asList(new String[] {
       "An", "African", "Swallow"}));
     assertEquals(list.size(), 6);
@@ -91,7 +84,7 @@ public class JUnitDemo {
   public static void main(String[] args) {
     // Invoke JUnit on the class:
     org.junit.runner.JUnitCore.runClasses(
-      JUnitDemo.class);
+      SimpleJUnit.class);
   }
 }
 /* Output: