Added more trivial core implementations.
diff --git a/net/api/src/main/java/org/onlab/onos/net/host/HostProviderService.java b/net/api/src/main/java/org/onlab/onos/net/host/HostProviderService.java
index 4c4859f..76c2aad 100644
--- a/net/api/src/main/java/org/onlab/onos/net/host/HostProviderService.java
+++ b/net/api/src/main/java/org/onlab/onos/net/host/HostProviderService.java
@@ -20,6 +20,6 @@
      *
      * @param hostDescription description of host
      */
-    void hostNotDetected(HostDescription hostDescription);
+    void hostVanished(HostDescription hostDescription);
 
 }