Change the license to GPL v3 to be compatible with Apache License 2.0.

HMCLAPI/src/main/java/rx/Subscription.java

@@ -0,0 +1,34 @@
+/**
+ * Copyright 2013 Netflix, Inc.
+ * 
+ * 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 rx;
+
+import rx.subscriptions.Subscriptions;
+
+/**
+ * Subscription returns from {@link Observable#subscribe(Observer)} to allow unsubscribing.
+ * <p>
+ * See utilities in {@link Subscriptions} and implementations in the {@link rx.subscriptions} package.
+ */
+public interface Subscription {
+
+    /**
+     * Stop receiving notifications on the {@link Observer} that was registered when this Subscription was received.
+     * <p>
+     * This allows unregistering an {@link Observer} before it has finished receiving all events (ie. before onCompleted is called).
+     */
+    public void unsubscribe();
+
+}