@Override
      public boolean evaluate(Object arg0) {
        return ((HostConfigMapping) arg0).getClusterId().equals(clusterId) 
            && ((HostConfigMapping) arg0).getSelected() > 0;
      }
Used for host configuration mapping operations.
ambari-server/src/main/java/org/apache/ambari/server/orm/dao/HostConfigMappingDAO.java