diff -r 4ebc2e2fb97c -r 71c04702a3d5 src/jdk.scripting.nashorn/share/classes/jdk/nashorn/api/scripting/AbstractJSObject.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/api/scripting/AbstractJSObject.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,226 @@
+/*
+ * Copyright (c) 2010, 2013, 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.nashorn.api.scripting;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Objects;
+import java.util.Set;
+
+/**
+ * This is the base class for nashorn ScriptObjectMirror class.
+ *
+ * This class can also be subclassed by an arbitrary Java class. Nashorn will
+ * treat objects of such classes just like nashorn script objects. Usual nashorn
+ * operations like obj[i], obj.foo, obj.func(), delete obj.foo will be delegated
+ * to appropriate method call of this class.
+ *
+ * @since 1.8u40
+ */
+public abstract class AbstractJSObject implements JSObject {
+    /**
+     * The default constructor.
+     */
+    public AbstractJSObject() {}
+
+    /**
+     * @implSpec This implementation always throws UnsupportedOperationException
+     */
+    @Override
+    public Object call(final Object thiz, final Object... args) {
+        throw new UnsupportedOperationException("call");
+    }
+
+    /**
+     * @implSpec This implementation always throws UnsupportedOperationException
+     */
+    @Override
+    public Object newObject(final Object... args) {
+        throw new UnsupportedOperationException("newObject");
+    }
+
+    /**
+     * @implSpec This imlementation always throws UnsupportedOperationException
+     */
+    @Override
+    public Object eval(final String s) {
+        throw new UnsupportedOperationException("eval");
+    }
+
+    /**
+     * @implSpec This implementation always returns null
+     */
+    @Override
+    public Object getMember(final String name) {
+        Objects.requireNonNull(name);
+        return null;
+    }
+
+    /**
+     * @implSpec This implementation always returns null
+     */
+    @Override
+    public Object getSlot(final int index) {
+        return null;
+    }
+
+    /**
+     * @implSpec This implementation always returns false
+     */
+    @Override
+    public boolean hasMember(final String name) {
+        Objects.requireNonNull(name);
+        return false;
+    }
+
+    /**
+     * @implSpec This implementation always returns false
+     */
+    @Override
+    public boolean hasSlot(final int slot) {
+        return false;
+    }
+
+    /**
+     * @implSpec This implementation is a no-op
+     */
+    @Override
+    public void removeMember(final String name) {
+        Objects.requireNonNull(name);
+        //empty
+    }
+
+    /**
+     * @implSpec This implementation is a no-op
+     */
+    @Override
+    public void setMember(final String name, final Object value) {
+        Objects.requireNonNull(name);
+        //empty
+    }
+
+    /**
+     * @implSpec This implementation is a no-op
+     */
+    @Override
+    public void setSlot(final int index, final Object value) {
+        //empty
+    }
+
+    // property and value iteration
+
+    /**
+     * @implSpec This implementation returns empty set
+     */
+    @Override
+    public Set<String> keySet() {
+        return Collections.emptySet();
+    }
+
+    /**
+     * @implSpec This implementation returns empty set
+     */
+    @Override
+    public Collection<Object> values() {
+        return Collections.emptySet();
+    }
+
+    // JavaScript instanceof check
+
+    /**
+     * @implSpec This implementation always returns false
+     */
+    @Override
+    public boolean isInstance(final Object instance) {
+        return false;
+    }
+
+    @Override
+    public boolean isInstanceOf(final Object clazz) {
+        if (clazz instanceof JSObject) {
+            return ((JSObject)clazz).isInstance(this);
+        }
+
+        return false;
+    }
+
+    @Override
+    public String getClassName() {
+        return getClass().getName();
+    }
+
+    /**
+     * @implSpec This implementation always returns false
+     */
+    @Override
+    public boolean isFunction() {
+        return false;
+    }
+
+    /**
+     * @implSpec This implementation always returns false
+     */
+    @Override
+    public boolean isStrictFunction() {
+        return false;
+    }
+
+    /**
+     * @implSpec This implementation always returns false
+     */
+    @Override
+    public boolean isArray() {
+        return false;
+    }
+
+    /**
+     * Returns this object's numeric value.
+     *
+     * @return this object's numeric value.
+     * @deprecated use {@link #getDefaultValue(Class)} with {@link Number} hint instead.
+     */
+    @Override @Deprecated
+    public double toNumber() {
+        return Double.NaN;
+    }
+
+    /**
+     * When passed an {@link AbstractJSObject}, invokes its {@link #getDefaultValue(Class)} method. When passed any
+     * other {@link JSObject}, it will obtain its {@code [[DefaultValue]]} method as per ECMAScript 5.1 section
+     * 8.6.2.
+     *
+     * @param jsobj the {@link JSObject} whose {@code [[DefaultValue]]} is obtained.
+     * @param hint the type hint. Should be either {@code null}, {@code Number.class} or {@code String.class}.
+     * @return this object's default value.
+     * @throws UnsupportedOperationException if the conversion can't be performed. The engine will convert this
+     * exception into a JavaScript {@code TypeError}.
+     * @deprecated use {@link JSObject#getDefaultValue(Class)} instead.
+     */
+    @Deprecated
+    public static Object getDefaultValue(final JSObject jsobj, final Class<?> hint) {
+        return jsobj.getDefaultValue(hint);
+    }
+}