--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.collections/src/org/graalvm/collections/Pair.java	Fri Feb 02 17:28:17 2018 -0800
@@ -0,0 +1,158 @@
+/*
+ * Copyright (c) 2017, 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 org.graalvm.collections;
+
+import java.util.Objects;
+
+/**
+ * Utility class representing a pair of values.
+ *
+ * @since 1.0
+ */
+public final class Pair<L, R> {
+
+    private static final Pair<Object, Object> EMPTY = new Pair<>(null, null);
+
+    private final L left;
+    private final R right;
+
+    /**
+     * Returns an empty pair.
+     *
+     * @since 1.0
+     */
+    @SuppressWarnings("unchecked")
+    public static <L, R> Pair<L, R> empty() {
+        return (Pair<L, R>) EMPTY;
+    }
+
+    /**
+     * Constructs a pair with its left value being {@code left}, or returns an empty pair if
+     * {@code left} is null.
+     *
+     * @return the constructed pair or an empty pair if {@code left} is null.
+     * @since 1.0
+     */
+    public static <L, R> Pair<L, R> createLeft(L left) {
+        if (left == null) {
+            return empty();
+        } else {
+            return new Pair<>(left, null);
+        }
+    }
+
+    /**
+     * Constructs a pair with its right value being {@code right}, or returns an empty pair if
+     * {@code right} is null.
+     *
+     * @return the constructed pair or an empty pair if {@code right} is null.
+     * @since 1.0
+     */
+    public static <L, R> Pair<L, R> createRight(R right) {
+        if (right == null) {
+            return empty();
+        } else {
+            return new Pair<>(null, right);
+        }
+    }
+
+    /**
+     * Constructs a pair with its left value being {@code left}, and its right value being
+     * {@code right}, or returns an empty pair if both inputs are null.
+     *
+     * @return the constructed pair or an empty pair if both inputs are null.
+     * @since 1.0
+     */
+    public static <L, R> Pair<L, R> create(L left, R right) {
+        if (right == null && left == null) {
+            return empty();
+        } else {
+            return new Pair<>(left, right);
+        }
+    }
+
+    private Pair(L left, R right) {
+        this.left = left;
+        this.right = right;
+    }
+
+    /**
+     * Returns the left value of this pair.
+     *
+     * @since 1.0
+     */
+    public L getLeft() {
+        return left;
+    }
+
+    /**
+     * Returns the right value of this pair.
+     *
+     * @since 1.0
+     */
+    public R getRight() {
+        return right;
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * @since 1.0
+     */
+    @Override
+    public int hashCode() {
+        return Objects.hashCode(left) + 31 * Objects.hashCode(right);
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * @since 1.0
+     */
+    @SuppressWarnings("unchecked")
+    @Override
+    public boolean equals(Object obj) {
+        if (obj == this) {
+            return true;
+        }
+
+        if (obj instanceof Pair) {
+            Pair<L, R> pair = (Pair<L, R>) obj;
+            return Objects.equals(left, pair.left) && Objects.equals(right, pair.right);
+        }
+
+        return false;
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * @since 1.0
+     */
+    @Override
+    public String toString() {
+        return String.format("(%s, %s)", left, right);
+    }
+}