ONOS-3633 - Implementation of virtual network point to point intent provider.

Change-Id: Ie2c1e5ac278bc0dd6259479c44dd92b9b625e90b
diff --git a/core/api/src/main/java/org/onosproject/net/DefaultLink.java b/core/api/src/main/java/org/onosproject/net/DefaultLink.java
index 739b47e..9aed9c9 100644
--- a/core/api/src/main/java/org/onosproject/net/DefaultLink.java
+++ b/core/api/src/main/java/org/onosproject/net/DefaultLink.java
@@ -148,7 +148,7 @@
     /**
      * Builder for DefaultLink objects.
      */
-    public static final class Builder {
+    public static class Builder {
         private ProviderId providerId;
         private Annotations annotations = EMPTY;
         private ConnectPoint src;
@@ -157,7 +157,7 @@
         private State state = ACTIVE;
         private boolean isExpected = false;
 
-        private Builder() {
+        protected Builder() {
             // Hide constructor
         }