/*
 * Copyright (c) 2014, 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 com.oracle.truffle.api.instrument;

import com.oracle.truffle.api.source.*;

/**
 * Instrumentation callback for guest language source-related events.
 */
public interface SourceCallback {

    public void startLoading(Source source);

    public void endLoading(Source source);
}

@@ -1486,11 +1486,272 @@
 source);
+%0A%0A    /**%0A     * Inert (singleton) implementation of %7B@link SourceCallback%7D.%0A     */%0A    SourceCallback NULL = new SourceCallback() %7B%0A%0A        public void startLoading(Source source) %7B%0A        %7D%0A%0A        public void endLoading(Source source) %7B%0A        %7D%0A%0A    %7D;
 %0A%7D%0A

add a singleton null instance of SourceCallback