--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/toolkit/util/UncheckedDocletException.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2016, 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.javadoc.internal.doclets.toolkit.util;
+
+import jdk.javadoc.internal.doclets.toolkit.DocletException;
+
+/**
+ * An unchecked exception that wraps a DocletException.
+ * It can be used in places where a checked exception
+ * is not permitted, such as in lambda expressions.
+ *
+ *  <p><b>This is NOT part of any supported API.
+ *  If you write code that depends on this, you do so at your own risk.
+ *  This code and its internal interfaces are subject to change or
+ *  deletion without notice.</b>
+ */
+public class UncheckedDocletException extends Error {
+    private static final long serialVersionUID = -9131058909576418984L;
+
+    public UncheckedDocletException(DocletException de) {
+        super(de);
+    }
+
+    @Override
+    public synchronized Throwable getCause() {
+        return super.getCause();
+    }
+
+    @Override
+    public synchronized Throwable initCause(Throwable cause) {
+        throw new UnsupportedOperationException();
+    }
+}