--- /dev/null	2017-01-22 10:16:57.869617664 -0800
+++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.core.common/src/org/graalvm/compiler/core/common/cfg/PrintableCFG.java	2017-02-15 16:57:05.849672133 -0800
@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2014, 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.
+ *
+ * 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 org.graalvm.compiler.core.common.cfg;
+
+import java.util.function.BiConsumer;
+
+/**
+ * Represents a control-flow graph where each node can be annotated with arbitrary property pairs of
+ * the form ({@linkplain String name}, {@linkplain String value}).
+ */
+public interface PrintableCFG {
+
+    AbstractBlockBase<?>[] getBlocks();
+
+    /**
+     * Applies {@code action} to all extra property pairs (name, value) of {@code block}.
+     *
+     * @param block a block from {@link #getBlocks()}.
+     * @param action a {@link BiConsumer consumer}.
+     */
+    default void forEachPropertyPair(AbstractBlockBase<?> block, BiConsumer<String, String> action) {
+        // no extra properties per default
+    }
+}