protected StringKeyMap<String> getPrimaryKeyMap(DfCustomizeEntityInfo entityInfo) {
   final StringKeyMap<String> pkMap = StringKeyMap.createAsFlexibleOrdered();
   final List<String> pkList = entityInfo.getPrimaryKeyList();
   if (pkList == null || pkList.isEmpty()) {
     return pkMap;
   }
   for (String pk : pkList) {
     if (Srl.contains(pk, ".")) {
       final IndexOfInfo info = Srl.indexOfFirst(pk, ".");
       String tableName = info.substringFrontTrimmed();
       String pkName = info.substringRearTrimmed();
       pkMap.put(pkName, tableName);
     } else {
       pkMap.put(pk, null); // no specified related table
     }
   }
   return pkMap;
 }