@Test
 public void lookupUnbound() throws Exception {
   registry.bind(KEY, VALUE);
   registry.unbind(KEY);
   final String result = registry.lookup(KEY);
   assertNull("Expectected value not to be bound", result);
 }
 @Test
 public void lookupNotBound() {
   final String result = registry.lookup(KEY);
   assertNull("Expectected value not to be bound", result);
 }
 @Test
 public void lookupBound() throws Exception {
   registry.bind(KEY, VALUE);
   final String result = registry.lookup(KEY);
   assertSame("Unexpected value found", VALUE, result);
 }