diff --git a/src/main/java/net/floodlightcontroller/linkdiscovery/internal/LinkStorageImpl.java b/src/main/java/net/floodlightcontroller/linkdiscovery/internal/LinkStorageImpl.java
index d0f0b9e..3aa1fc0 100644
--- a/src/main/java/net/floodlightcontroller/linkdiscovery/internal/LinkStorageImpl.java
+++ b/src/main/java/net/floodlightcontroller/linkdiscovery/internal/LinkStorageImpl.java
@@ -248,7 +248,7 @@
 	
 		@Override
 		public Link compute(PathPipe<Vertex> pipe ) {
-
+			// TODO Auto-generated method stub
 			long s_dpid = 0;
 			long d_dpid = 0;
 			short s_port = 0;
@@ -269,6 +269,16 @@
 			return l;
 		}
 	}
+	
+	public void finalize() {
+		close();
+	}
+
+	@Override
+	public void close() {
+		// TODO Auto-generated method stub
+		graph.shutdown();		
+	}
 
 
 }
diff --git a/src/main/java/net/floodlightcontroller/linkdiscovery/internal/TopoLinkServiceImpl.java b/src/main/java/net/floodlightcontroller/linkdiscovery/internal/TopoLinkServiceImpl.java
index b73224e..2dbb338 100644
--- a/src/main/java/net/floodlightcontroller/linkdiscovery/internal/TopoLinkServiceImpl.java
+++ b/src/main/java/net/floodlightcontroller/linkdiscovery/internal/TopoLinkServiceImpl.java
@@ -21,7 +21,8 @@
 	@Override
 	public List<Link> GetActiveLinks() {
 		// TODO Auto-generated method stub
-		return linkStore.getActiveLinks();
+		List<Link> retval = linkStore.getActiveLinks();
+		return retval;
 	}
 
 	@Override
@@ -29,5 +30,4 @@
 		// TODO Auto-generated method stub
 		return linkStore.getLinks(dpid);
 	}
-
 }
diff --git a/src/main/java/net/floodlightcontroller/linkdiscovery/web/TopoLinksResource.java b/src/main/java/net/floodlightcontroller/linkdiscovery/web/TopoLinksResource.java
index 323708e..a0770cb 100644
--- a/src/main/java/net/floodlightcontroller/linkdiscovery/web/TopoLinksResource.java
+++ b/src/main/java/net/floodlightcontroller/linkdiscovery/web/TopoLinksResource.java
@@ -13,8 +13,8 @@
     public List<Link> retrieve() {
 		TopoLinkServiceImpl impl = new TopoLinkServiceImpl();
 		
-		return impl.GetActiveLinks();
-		
+		List<Link> retval = impl.GetActiveLinks();
+		return retval;
 	}
 
 }