--- /dev/null	2016-05-31 09:42:47.975716356 -0700
+++ new/src/jdk.vm.compiler/share/classes/org.graalvm.compiler.debug.test/src/org/graalvm/compiler/debug/test/DebugHistogramTest.java	2016-12-09 00:48:07.235695077 -0800
@@ -0,0 +1,127 @@
+/*
+ * Copyright (c) 2013, 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.
+ *
+ * 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.debug.test;
+
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import org.graalvm.compiler.debug.Debug;
+import org.graalvm.compiler.debug.DebugHistogram;
+import org.graalvm.compiler.debug.internal.DebugHistogramAsciiPrinter;
+import org.graalvm.compiler.debug.internal.DebugHistogramRPrinter;
+
+public class DebugHistogramTest {
+
+    @Test
+    public void testEmptyHistogram() {
+        DebugHistogram histogram = Debug.createHistogram("TestHistogram");
+        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+
+        new DebugHistogramAsciiPrinter(new PrintStream(outputStream)).print(histogram);
+        String line = outputStream.toString().split("\r?\n")[0];
+        Assert.assertEquals("TestHistogram is empty.", line);
+
+        outputStream.reset();
+        new DebugHistogramRPrinter(new PrintStream(outputStream)).print(histogram);
+        Assert.assertEquals("", outputStream.toString());
+    }
+
+    @Test
+    public void testSingleEntryHistogram() {
+        DebugHistogram histogram = Debug.createHistogram("TestHistogram");
+        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+        histogram.add(new Integer(1));
+        histogram.add(new Integer(1));
+        new DebugHistogramAsciiPrinter(new PrintStream(outputStream)).print(histogram);
+        String[] lines = outputStream.toString().split("\r?\n");
+        // @formatter:off
+        String[] expected = {
+            "TestHistogram has 1 unique elements and 2 total elements:",
+            "--------------------------------------------------------------------------------------------------------------------------------------------------------------------------",
+            "| 1                                                  | 2          | ==================================================================================================== |",
+            "--------------------------------------------------------------------------------------------------------------------------------------------------------------------------"
+        };
+        // @formatter:on
+        Assert.assertArrayEquals(expected, lines);
+
+        outputStream.reset();
+        new DebugHistogramRPrinter(new PrintStream(outputStream)).print(histogram);
+        lines = outputStream.toString().split("\r?\n");
+        // @formatter:off
+        expected = new String[] {
+            "TestHistogram <- c(2);",
+            "names(TestHistogram) <- c(\"1\");"
+        };
+        // @formatter:on
+        Assert.assertArrayEquals(expected, lines);
+    }
+
+    @Test
+    public void testMultipleEntryHistogram() {
+        DebugHistogram histogram = Debug.createHistogram("TestHistogram");
+        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+        histogram.add(new Integer(1));
+        histogram.add(new Integer(2));
+        histogram.add(new Integer(2));
+        new DebugHistogramAsciiPrinter(new PrintStream(outputStream)).print(histogram);
+        String[] lines = outputStream.toString().split("\r?\n");
+        // @formatter:off
+        String[] expected = new String[] {
+            "TestHistogram has 2 unique elements and 3 total elements:",
+            "--------------------------------------------------------------------------------------------------------------------------------------------------------------------------",
+            "| 2                                                  | 2          | ==================================================================================================== |",
+            "| 1                                                  | 1          | ==================================================                                                   |",
+            "--------------------------------------------------------------------------------------------------------------------------------------------------------------------------"
+        };
+        // @formatter:on
+        Assert.assertArrayEquals(expected, lines);
+
+        outputStream.reset();
+        new DebugHistogramRPrinter(new PrintStream(outputStream)).print(histogram);
+        lines = outputStream.toString().split("\r?\n");
+        // @formatter:off
+        expected = new String[] {
+            "TestHistogram <- c(2, 1);",
+            "names(TestHistogram) <- c(\"2\", \"1\");"
+        };
+        // @formatter:on
+        Assert.assertArrayEquals(expected, lines);
+    }
+
+    @Test
+    public void testTooLongValueString() {
+        DebugHistogram histogram = Debug.createHistogram("TestHistogram");
+        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+        histogram.add("MyCustomValue");
+        new DebugHistogramAsciiPrinter(new PrintStream(outputStream), Integer.MAX_VALUE, 10, 10, 1).print(histogram);
+        String[] lines = outputStream.toString().split("\r?\n");
+        Assert.assertEquals(4, lines.length);
+        Assert.assertEquals("TestHistogram has 1 unique elements and 1 total elements:", lines[0]);
+        Assert.assertEquals("----------------------------------------", lines[1]);
+        Assert.assertEquals("| MyCusto... | 1          | ========== |", lines[2]);
+        Assert.assertEquals("----------------------------------------", lines[3]);
+    }
+}