Travis CI failing on this

Bruce Eckel · Bruce Eckel · commit f26eb5689e85 · 2017-01-17T07:31:29.000-08:00
diff --git a/concurrent/Summing2.java b/concurrent/Summing2.java
@@ -2,6 +2,7 @@
 // (c)2017 MindView LLC: see Copyright.txt
 // We make no guarantees that this code is fit for any purpose.
 // Visit http://OnJava8.com for more book information.
+// {ValidateByHand} // CI has trouble
 import java.util.*;
 
 public class Summing2 {
