Added Host related memos.

Change-Id: Idbbce6a72b6f7fecc6691f2af68f4ce40b58ca34
diff --git a/core/api/src/main/java/org/onlab/onos/net/host/HostDescription.java b/core/api/src/main/java/org/onlab/onos/net/host/HostDescription.java
index f45a383..fc16854 100644
--- a/core/api/src/main/java/org/onlab/onos/net/host/HostDescription.java
+++ b/core/api/src/main/java/org/onlab/onos/net/host/HostDescription.java
@@ -37,6 +37,7 @@
      *
      * @return host IP address
      */
+    // FIXME: Switch to IpAddress
     IpPrefix ipAddress();
 
 }