@RequiresSession
  public Set<ConfigGroupHostMapping> findByHostId(Long hostId) {

    populateCache();

    if (!configGroupHostMappingByHost.containsKey(hostId)) {
      return null;
    }

    Set<ConfigGroupHostMapping> set = new HashSet<>(configGroupHostMappingByHost.get(hostId));

    return set;

  }
Return entity object which can be used for operations like remove
directly.
@param configGroupHostMappingEntityPK
@return
ambari-server/src/main/java/org/apache/ambari/server/orm/dao/ConfigGroupHostMappingDAO.java