diff -r 89829dd3cc54 -r b1c1b4ef4be2 src/jdk.incubator.httpclient/share/classes/jdk/incubator/http/AbstractSubscription.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.incubator.httpclient/share/classes/jdk/incubator/http/AbstractSubscription.java	Wed Dec 06 11:11:59 2017 -0800
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.incubator.http;
+
+import java.util.concurrent.Flow;
+import jdk.incubator.http.internal.common.Demand;
+
+/**
+ * A {@link Flow.Subscription} wrapping a {@link Demand} instance.
+ *
+ */
+abstract class AbstractSubscription implements Flow.Subscription {
+
+    private final Demand demand = new Demand();
+
+    /**
+     * Returns the subscription's demand.
+     * @return the subscription's demand.
+     */
+    protected Demand demand() { return demand; }
+
+}