Revise Javadoc

- Remove the word "path" as no ResourcePath anymore
- Write conditions that a method throws an exception

Change-Id: Ie2f2e1cfd1c6c68051e6700ef4308363a71d9453
diff --git a/core/api/src/main/java/org/onosproject/net/newresource/ResourceId.java b/core/api/src/main/java/org/onosproject/net/newresource/ResourceId.java
index ee1660d..262cef2 100644
--- a/core/api/src/main/java/org/onosproject/net/newresource/ResourceId.java
+++ b/core/api/src/main/java/org/onosproject/net/newresource/ResourceId.java
@@ -30,7 +30,7 @@
     /**
      * Returns the parent resource ID of this instance.
      *
-     * @return the parent resource path of this instance.
+     * @return the parent resource ID of this instance.
      * If there is no parent, empty instance will be returned.
      */
     public abstract Optional<DiscreteResourceId> parent();