Adding mode base model and unit tests stuff.
diff --git a/net/api/src/main/java/org/onlab/onos/net/DefaultDevice.java b/net/api/src/main/java/org/onlab/onos/net/DefaultDevice.java
new file mode 100644
index 0000000..42a3526
--- /dev/null
+++ b/net/api/src/main/java/org/onlab/onos/net/DefaultDevice.java
@@ -0,0 +1,103 @@
+package org.onlab.onos.net;
+
+import org.onlab.onos.net.provider.ProviderId;
+
+import java.util.Objects;
+
+import static com.google.common.base.Objects.toStringHelper;
+
+/**
+ * Default device model implementation.
+ */
+public class DefaultDevice extends AbstractElement implements Device {
+
+    private final Type type;
+    private final String manufacturer;
+    private final String serialNumber;
+    private final String hwVersion;
+    private final String swVersion;
+
+    /**
+     * Creates a network element attributed to the specified provider.
+     *
+     * @param providerId   identity of the provider
+     * @param id           device identifier
+     * @param type         device type
+     * @param manufacturer device manufacturer
+     * @param hwVersion    device HW version
+     * @param swVersion    device SW version
+     * @param serialNumber device serial number
+     */
+    public DefaultDevice(ProviderId providerId, DeviceId id, Type type,
+                         String manufacturer, String hwVersion, String swVersion,
+                         String serialNumber) {
+        super(providerId, id);
+        this.type = type;
+        this.manufacturer = manufacturer;
+        this.hwVersion = hwVersion;
+        this.swVersion = swVersion;
+        this.serialNumber = serialNumber;
+    }
+
+    @Override
+    public DeviceId id() {
+        return (DeviceId) super.id();
+    }
+
+    @Override
+    public Type type() {
+        return type;
+    }
+
+    @Override
+    public String manufacturer() {
+        return manufacturer;
+    }
+
+    @Override
+    public String hwVersion() {
+        return hwVersion;
+    }
+
+    @Override
+    public String swVersion() {
+        return swVersion;
+    }
+
+    @Override
+    public String serialNumber() {
+        return serialNumber;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(id, type, manufacturer, hwVersion, swVersion, serialNumber);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj instanceof DefaultDevice) {
+            final DefaultDevice other = (DefaultDevice) obj;
+            return Objects.equals(this.id, other.id) &&
+                    Objects.equals(this.type, other.type) &&
+                    Objects.equals(this.manufacturer, other.manufacturer) &&
+                    Objects.equals(this.hwVersion, other.hwVersion) &&
+                    Objects.equals(this.swVersion, other.swVersion) &&
+                    Objects.equals(this.serialNumber, other.serialNumber);
+        }
+        return false;
+    }
+
+    @Override
+    public String toString() {
+        return toStringHelper(this)
+                .add("id", id)
+                .add("type", type)
+                .add("manufacturer", manufacturer)
+                .add("hwVersion", hwVersion)
+                .add("swVersion", swVersion)
+                .add("serialNumber", serialNumber)
+                .toString();
+    }
+
+}