This interface is for returning controls with objects returned in NamingEnumerations.

  This interface is for returning controls with objects returned
in NamingEnumerations.
For example, suppose a server sends back controls with the results
of a search operation, the service provider would return a NamingEnumeration of
objects that are both SearchResult and implement HasControls.

   NamingEnumeration elts = ectx.search((Name)name, filter, sctls);
   while (elts.hasMore()) {
        Object entry = elts.next();

        // Get search result 
        SearchResult res = (SearchResult)entry;
        // do something with it 

        // Get entry controls
        if (entry instanceof HasControls) {
            Control[] entryCtls = ((HasControls)entry).getControls();
            // do something with controls
        }
   }