--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.jshell/share/classes/jdk/internal/jshell/tool/ConsoleIOContextTestSupport.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,41 @@
+/*
+ * 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.internal.jshell.tool;
+
+/**A support class to the ConsoleIOContext, containing callbacks called
+ * on important points in ConsoleIOContext.
+ */
+public abstract class ConsoleIOContextTestSupport {
+
+    public static ConsoleIOContextTestSupport IMPL;
+
+    public static void willComputeCompletion() {
+        if (IMPL != null)
+            IMPL.willComputeCompletionCallback();
+    }
+
+    protected abstract void willComputeCompletionCallback();
+
+}