Fixes LinkCollection compiler

Changes:
- adds the ability to handle co-located ingress/egress points;
- adds new unit tests to test the proper handling;

Change-Id: I63da5057e716cc94fcca8f13debafc44633b6820
diff --git a/core/net/src/test/java/org/onosproject/net/intent/impl/compiler/AbstractLinkCollectionTest.java b/core/net/src/test/java/org/onosproject/net/intent/impl/compiler/AbstractLinkCollectionTest.java
index 38aad30..bd2c7c7 100644
--- a/core/net/src/test/java/org/onosproject/net/intent/impl/compiler/AbstractLinkCollectionTest.java
+++ b/core/net/src/test/java/org/onosproject/net/intent/impl/compiler/AbstractLinkCollectionTest.java
@@ -91,8 +91,6 @@
             link(d2p1, d3p0)
     );
 
-
-
     final Set<Link> linksForSp2Mp = ImmutableSet.of(
             link(d3p0, d2p1),
             link(d2p0, d1p0)
@@ -103,6 +101,15 @@
             link(d2p1, d3p1)
     );
 
+    final Set<Link> linksForSp2MpCoLoc = ImmutableSet.of(
+            link(d1p0, d2p0),
+            link(d2p1, d3p0)
+    );
+
+    final Set<Link> linksForMp2SpCoLoc = ImmutableSet.of(
+            link(d2p0, d1p0)
+    );
+
     final TrafficTreatment treatment = emptyTreatment();
     final TrafficTreatment ethDstTreatment = macDstTreatment("C0:FF:EE:C0:FF:EE");
     final TrafficTreatment decTllTreatment = decTtlTreatment();