--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/tests/gov/nasa/jpf/util/IdentityArrayObjectSetTest.java	Fri Jan 23 10:14:01 2015 -0800
@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2014, United States Government, as represented by the
+ * Administrator of the National Aeronautics and Space Administration.
+ * All rights reserved.
+ *
+ * The Java Pathfinder core (jpf-core) platform is 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 gov.nasa.jpf.util;
+
+import gov.nasa.jpf.util.test.TestJPF;
+import org.junit.Test;
+
+/**
+ * regression test for IdentityArrayObjectSet
+ */
+public class IdentityArrayObjectSetTest extends TestJPF {
+
+  @Test
+  public void testBasic(){
+    String a = "a";
+    String b = "b";
+    
+    IdentityArrayObjectSet<String> s = new IdentityArrayObjectSet<String>();
+    
+    assertTrue(  s.isEmpty());
+    System.out.println(s);
+
+    assertTrue(  s.add(a));
+    assertTrue(  s.size() == 1);
+    assertTrue(  s.contains(a));
+    System.out.println(s);
+    
+    assertFalse( s.add(a)); // already in
+    assertTrue(  s.size() == 1);
+    System.out.println(s);
+    
+    assertTrue(  s.add(b));
+    assertTrue(  s.size() == 2);
+    assertTrue(  s.contains(b));
+    System.out.println(s);
+
+    assertTrue(  s.remove(a));
+    assertTrue(  s.size() == 1);
+    assertFalse( s.contains(a));
+    assertTrue(  s.contains(b));
+    System.out.println(s);
+    
+    assertFalse( s.remove(a)); // can't remove it a second time
+    System.out.println(s);
+    
+    assertTrue(  s.remove(b));
+    assertTrue(  s.isEmpty());
+    System.out.println(s);
+  }
+}