code: @SuppressWarnings("unchecked")
    private boolean hasPropertiesConfiguration(Dictionary properties) {
      HashMap<Object, Object> mapProperties = new HashMap<Object, Object>(properties.size());
      for (Object key : Collections.list(properties.keys())) {
        mapProperties.put(key, properties.get(key));
      }
      mapProperties.remove(Constants.SERVICE_PID);
      mapProperties.remove("service.factoryPid");
      return !mapProperties.isEmpty();
    }
docs: It happends that the factory get called with properties that only contain
  service.pid and service.factoryPid. If that happens we don't want to create
  an engine.
  
  @param properties
  @return