Singletons can only include one instance of each class.
svn path=/trunk/; revision=438
diff --git a/src/jsr311-api/src/javax/ws/rs/core/Application.java b/src/jsr311-api/src/javax/ws/rs/core/Application.java
index 5f7c07a..b5eccd9 100644
--- a/src/jsr311-api/src/javax/ws/rs/core/Application.java
+++ b/src/jsr311-api/src/javax/ws/rs/core/Application.java
@@ -47,7 +47,9 @@
* (see {@link Context}) prior to use.
*
* <p>Implementations should warn about and ignore classes that do not
- * conform to the requirements of root resource or provider classes.</p>
+ * conform to the requirements of root resource or provider classes.
+ * Implementations should flag an error if the returned set includes
+ * more than one instance of the same class.</p>
*
* <p>The default implementation returns an empty set.</p>
*
