Refactored the topology provider.

+package org.onlab.onos.net.trivial.topology.provider.impl;
+
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.topology.TopoEdge;
+import org.onlab.onos.net.topology.TopoVertex;
+
+import java.util.Objects;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+
+/**
+ * Implementation of the topology edge backed by a link.
+ */
+class DefaultTopoEdge implements TopoEdge {
+
+    private final Link link;
+    private final TopoVertex src;
+    private final TopoVertex dst;
+
+    /**
+     * Creates a new topology edge.
+     *
+     * @param src  source vertex
+     * @param dst  destination vertex
+     * @param link infrastructure link
+     */
+    DefaultTopoEdge(TopoVertex src, TopoVertex dst, Link link) {
+        this.src = src;
+        this.dst = dst;
+        this.link = link;
+    }
+
+    @Override
+    public Link link() {
+        return link;
+    }
+
+    @Override
+    public TopoVertex src() {
+        return src;
+    }
+
+    @Override
+    public TopoVertex dst() {
+        return dst;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(link);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj instanceof DefaultTopoEdge) {
+            final DefaultTopoEdge other = (DefaultTopoEdge) obj;
+            return Objects.equals(this.link, other.link);
+        }
+        return false;
+    }
+
+    @Override
+    public String toString() {
+        return toStringHelper(this).add("src", src).add("dst", dst).toString();
+    }
+
+}
+

+package org.onlab.onos.net.trivial.topology.provider.impl;
+
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.topology.TopoVertex;
+
+import java.util.Objects;
+
+/**
+ * Implementation of the topology vertex backed by a device id.
+ */
+class DefaultTopoVertex implements TopoVertex {
+
+    private final DeviceId deviceId;
+
+    /**
+     * Creates a new topology vertex.
+     *
+     * @param deviceId backing infrastructure device identifier
+     */
+    DefaultTopoVertex(DeviceId deviceId) {
+        this.deviceId = deviceId;
+    }
+
+    @Override
+    public DeviceId deviceId() {
+        return deviceId;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(deviceId);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj instanceof DefaultTopoVertex) {
+            final DefaultTopoVertex other = (DefaultTopoVertex) obj;
+            return Objects.equals(this.deviceId, other.deviceId);
+        }
+        return false;
+    }
+
+    @Override
+    public String toString() {
+        return deviceId.toString();
+    }
+
+}
+

@@ -115,7 +115,6 @@ public class SimpleTopologyProvider extends AbstractProvider
     // Builds the topology using the latest device and link information
     // Builds the topology using the latest device and link information
     // and citing the specified events as reasons for the change.
     // and citing the specified events as reasons for the change.
     private void buildTopology(List<Event> reasons) {
     private void buildTopology(List<Event> reasons) {
-        log.info("YO! Computing topology");
         if (isStarted) {
         if (isStarted) {
             TopologyDescription desc =
             TopologyDescription desc =
                     new DefaultTopologyDescription(System.nanoTime(),
                     new DefaultTopologyDescription(System.nanoTime(),