code: public Iterator getCurrentServiceClasses() {
  
          ArrayList<Class> currentClasses = new ArrayList<Class>();
          for (Class serviceClass : _serviceProviders.keySet()) {
              ServiceProvider sp = _serviceProviders.get(serviceClass);
              if (!sp.isRevoked() && !sp.isDelegated()) {
                  currentClasses.add(serviceClass);
              }
          }
          return currentClasses.iterator();
      }
docs: Gets the currently available services for this context.
  
  @return an <code>Iterator</code> consisting of the
  currently available services