Fixed annotation handling.

- Store as SparseAnnotations internally and convert to Annotations
  when merging multiple provider supplied annotations.

Change-Id: I82fe159b536b3e7344a33e09792f6a3473fb3500
diff --git a/core/api/src/test/java/org/onlab/onos/net/DefaultDeviceTest.java b/core/api/src/test/java/org/onlab/onos/net/DefaultDeviceTest.java
index b4018e3..329e128 100644
--- a/core/api/src/test/java/org/onlab/onos/net/DefaultDeviceTest.java
+++ b/core/api/src/test/java/org/onlab/onos/net/DefaultDeviceTest.java
@@ -58,7 +58,5 @@
         assertEquals("incorrect hw", HW, device.hwVersion());
         assertEquals("incorrect sw", SW, device.swVersion());
         assertEquals("incorrect serial", SN1, device.serialNumber());
-        assertEquals("incorrect serial", SN1, device.serialNumber());
     }
-
-}
\ No newline at end of file
+}