@Test
 public void testCopy() {
   OpenDoubleObjectHashMap<TestClass> map = new OpenDoubleObjectHashMap<TestClass>();
   map.put((double) 11, item);
   OpenDoubleObjectHashMap<TestClass> map2 = (OpenDoubleObjectHashMap<TestClass>) map.copy();
   map.clear();
   assertEquals(1, map2.size());
 }
 @Test
 public void testClear() {
   OpenDoubleObjectHashMap<TestClass> map = new OpenDoubleObjectHashMap<TestClass>();
   map.put((double) 11, item);
   assertEquals(1, map.size());
   map.clear();
   assertEquals(0, map.size());
   assertSame(null, map.get((double) 11));
 }