adding javadoc to LinkResourceService

Change-Id: I2319c6cca4b1f051be453f1c87f5aba2773027f9
diff --git a/core/api/src/main/java/org/onlab/onos/net/resource/LinkResourceService.java b/core/api/src/main/java/org/onlab/onos/net/resource/LinkResourceService.java
index 973fa97..e7988df 100644
--- a/core/api/src/main/java/org/onlab/onos/net/resource/LinkResourceService.java
+++ b/core/api/src/main/java/org/onlab/onos/net/resource/LinkResourceService.java
@@ -30,6 +30,12 @@
      */
     Iterable<LinkResourceAllocations> getAllocations();
 
+    /**
+     * Returns the resources allocated for an Intent.
+     *
+     * @param intentId the target Intent's id
+     * @return allocated resources for Intent
+     */
     LinkResourceAllocations getAllocation(IntentId intentId);
 
     /**