diff --git a/gson/src/test/java/com/google/gson/functional/JsonParserTest.java b/gson/src/test/java/com/google/gson/functional/JsonParserTest.java
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+++ b/gson/src/test/java/com/google/gson/functional/JsonParserTest.java
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2008 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.gson.functional;
+
+import com.google.gson.Gson;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParser;
+import com.google.gson.common.TestTypes.BagOfPrimitives;
+
+import junit.framework.TestCase;
+
+import java.io.StringReader;
+
+/**
+ * Functional tests for that use JsonParser and related Gson methods
+ *
+ * @author Inderjeet Singh
+ * @author Joel Leitch
+ */
+public class JsonParserTest extends TestCase {
+  private Gson gson;
+
+  @Override
+  protected void setUp() throws Exception {
+    super.setUp();
+    gson = new Gson();
+  }
+  
+  public void testDeserializingCustomTree() {
+    JsonObject obj = new JsonObject();
+    obj.addProperty("stringValue", "foo");
+    obj.addProperty("intValue", 11);
+    BagOfPrimitives target = gson.fromJson(obj, BagOfPrimitives.class);
+    assertEquals(11, target.intValue);
+    assertEquals("foo", target.stringValue);
+  }
+
+  public void testChangingCustomTreeAndDeserializing() {
+    StringReader json = 
+      new StringReader("{'stringValue':'no message','intValue':10,'longValue':20}");
+    JsonObject obj = (JsonObject) JsonParser.parse(json);
+    obj.remove("stringValue");
+    obj.addProperty("stringValue", "fooBar");
+    BagOfPrimitives target = gson.fromJson(obj, BagOfPrimitives.class);
+    assertEquals(10, target.intValue);
+    assertEquals(20, target.longValue);
+    assertEquals("fooBar", target.stringValue);
+  }
+}