diff --git a/src/test/java/org/jboss/netty/util/MapBackedSetTest.java b/src/test/java/org/jboss/netty/util/MapBackedSetTest.java
new file mode 100644
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+++ b/src/test/java/org/jboss/netty/util/MapBackedSetTest.java
@@ -0,0 +1,123 @@
+/*
+ * JBoss, Home of Professional Open Source
+ *
+ * Copyright 2008, Red Hat Middleware LLC, and individual contributors
+ * by the @author tags. See the COPYRIGHT.txt in the distribution for a
+ * full listing of individual contributors.
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This software 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this software; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
+ */
+package org.jboss.netty.util;
+
+import static org.easymock.EasyMock.*;
+import static org.junit.Assert.*;
+
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Set;
+
+import org.junit.Test;
+
+
+/**
+ * @author The Netty Project (netty-dev@lists.jboss.org)
+ * @author Trustin Lee (tlee@redhat.com)
+ *
+ * @version $Rev$, $Date$
+ *
+ */
+public class MapBackedSetTest {
+
+    @Test
+    @SuppressWarnings("unchecked")
+    public void testSize() {
+        Map map = createStrictMock(Map.class);
+        expect(map.size()).andReturn(0);
+        replay(map);
+
+        assertEquals(0, new MapBackedSet(map).size());
+        verify(map);
+    }
+
+    @Test
+    @SuppressWarnings("unchecked")
+    public void testContains() {
+        Map map = createStrictMock(Map.class);
+        expect(map.containsKey("key")).andReturn(true);
+        replay(map);
+
+        assertTrue(new MapBackedSet(map).contains("key"));
+        verify(map);
+    }
+
+
+    @Test
+    @SuppressWarnings("unchecked")
+    public void testRemove() {
+        Map map = createStrictMock(Map.class);
+        expect(map.remove("key")).andReturn(true);
+        expect(map.remove("key")).andReturn(null);
+        replay(map);
+
+        assertTrue(new MapBackedSet(map).remove("key"));
+        assertFalse(new MapBackedSet(map).remove("key"));
+        verify(map);
+    }
+
+    @Test
+    @SuppressWarnings("unchecked")
+    public void testAdd() {
+        Map map = createStrictMock(Map.class);
+        expect(map.put("key", true)).andReturn(null);
+        expect(map.put("key", true)).andReturn(true);
+        replay(map);
+
+        assertTrue(new MapBackedSet(map).add("key"));
+        assertFalse(new MapBackedSet(map).add("key"));
+        verify(map);
+    }
+
+    @Test
+    @SuppressWarnings("unchecked")
+    public void testClear() {
+        Map map = createStrictMock(Map.class);
+        map.clear();
+        replay(map);
+
+        new MapBackedSet(map).clear();
+        verify(map);
+    }
+
+    @Test
+    @SuppressWarnings("unchecked")
+    public void testIterator() {
+        Map map = createStrictMock(Map.class);
+        Set keySet = createStrictMock(Set.class);
+        Iterator keySetIterator = createStrictMock(Iterator.class);
+
+        expect(map.keySet()).andReturn(keySet);
+        expect(keySet.iterator()).andReturn(keySetIterator);
+        replay(map);
+        replay(keySet);
+        replay(keySetIterator);
+
+        assertSame(keySetIterator, new MapBackedSet(map).iterator());
+
+        verify(map);
+        verify(keySet);
+        verify(keySetIterator);
+    }
+}