[CORD-2432][CORD-2431] Initial t3 implementation

Change-Id: I1ed421f82c234bb006ed2cefefea53d773f1efc9
diff --git a/apps/t3/src/main/java/org/onosproject/t3/api/GroupsInDevice.java b/apps/t3/src/main/java/org/onosproject/t3/api/GroupsInDevice.java
new file mode 100644
index 0000000..3cfb41a
--- /dev/null
+++ b/apps/t3/src/main/java/org/onosproject/t3/api/GroupsInDevice.java
@@ -0,0 +1,81 @@
+/*
+ * Copyright 2017-present Open Networking Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.t3.api;
+
+import org.onosproject.net.ConnectPoint;
+import org.onosproject.net.flow.TrafficSelector;
+import org.onosproject.net.group.Group;
+
+import java.util.List;
+
+/**
+ * Class to represent the groups in a device for a given output and packet.
+ */
+//FIXME consider removing.
+public class GroupsInDevice {
+
+    private ConnectPoint output;
+    private List<Group> groups;
+    private TrafficSelector selector;
+
+    /**
+     * Saves the given groups for the output connect point and the selector.
+     * @param output the output connect point
+     * @param groups the groups
+     * @param selector the selector representing the final packet
+     */
+    public GroupsInDevice(ConnectPoint output, List<Group> groups, TrafficSelector selector) {
+
+        this.output = output;
+        this.groups = groups;
+        this.selector = selector;
+    }
+
+    /**
+     * Returns the output connect point.
+     * @return the connect point
+     */
+    public ConnectPoint getOutput() {
+        return output;
+    }
+
+    /**
+     * Returns the groups.
+     * @return groups.
+     */
+    public List<Group> getGroups() {
+        return groups;
+    }
+
+    /**
+     * Returns the final packet after traversing the network.
+     * @return the selector with packet info
+     */
+    public TrafficSelector getFinalPacket() {
+        return selector;
+    }
+
+    @Override
+    public String toString() {
+        return "GroupsInDevice{" +
+                "output=" + output +
+                ", groups=" + groups +
+                ", selector=" + selector +
+                '}';
+    }
+
+}