@Override
  public int hashCode() {
    int result = clusterId !=null ? clusterId.intValue() : 0;
    result = 31 * result + (type != null ? type.hashCode() : 0);
    result = 31 * result + (hostId != null ? hostId.hashCode() : 0);
    result = 31 * result + createTimestamp.intValue();
    return result;
  }
PK class for host config mappings.
ambari-server/src/main/java/org/apache/ambari/server/orm/entities/HostConfigMappingEntityPK.java