diff -r 81d72f69fa42 -r 40cabcdcd2be samples/covariance/src-impl/test/CovarianceTest.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/samples/covariance/src-impl/test/CovarianceTest.java	Thu Oct 30 21:30:10 2014 +0100
@@ -0,0 +1,13 @@
+package test;
+
+import api.Covariance;
+
+public class CovarianceTest {
+    // BEGIN: variance.covariance.test
+    public static void main(String[] args) {
+        Number n = Covariance.max(10, 20);
+        System.err.println("value: " + n + " type: " + n.getClass());
+        assert n.intValue() == 20 : "The max should be 20, but was: " + n;
+    }
+    // END: variance.covariance.test
+}