Consolidating null providers and making them fully configurable and integrated with the ConfigProvider to allow arbitrary topologies.

Change-Id: I899e27a9771af4013a3ce6da7f683a4927ffb438
diff --git a/cli/src/main/java/org/onosproject/cli/UpDownCompleter.java b/cli/src/main/java/org/onosproject/cli/UpDownCompleter.java
new file mode 100644
index 0000000..9d8eda5
--- /dev/null
+++ b/cli/src/main/java/org/onosproject/cli/UpDownCompleter.java
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * 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.cli;
+
+import com.google.common.collect.ImmutableList;
+
+import java.util.List;
+
+/**
+ * Up/down command completer.
+ */
+public class UpDownCompleter extends AbstractChoicesCompleter {
+
+    public static final String UP = "up";
+    public static final String DOWN = "down";
+
+    @Override
+    public List<String> choices() {
+        return ImmutableList.of(UP, DOWN);
+    }
+}