Initial implementation of the intent domain manager

Change-Id: I9721449599a4a67bfad7469173c3b47a681873f6
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/config/basics/SubjectFactories.java b/incubator/api/src/main/java/org/onosproject/incubator/net/config/basics/SubjectFactories.java
index a91a352..0ba9459 100644
--- a/incubator/api/src/main/java/org/onosproject/incubator/net/config/basics/SubjectFactories.java
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/config/basics/SubjectFactories.java
@@ -18,6 +18,7 @@
 import org.onosproject.core.ApplicationId;
 import org.onosproject.core.CoreService;
 import org.onosproject.incubator.net.config.SubjectFactory;
+import org.onosproject.incubator.net.domain.IntentDomainId;
 import org.onosproject.net.ConnectPoint;
 import org.onosproject.net.DeviceId;
 import org.onosproject.net.HostId;
@@ -80,6 +81,14 @@
                 }
             };
 
+    public static final SubjectFactory<IntentDomainId> INTENT_DOMAIN_SUBJECT_FACTORY =
+            new SubjectFactory<IntentDomainId>(IntentDomainId.class, "domains") {
+                @Override
+                public IntentDomainId createSubject(String key) {
+                    return IntentDomainId.valueOf(key);
+                }
+            };
+
     /**
      * Provides reference to the core service, which is required for
      * application subject factory.