code: private Instance getExistingLocale(final long _propertyid,
                                         final String _language)
      {
          Instance ret = null;
          try {
              final QueryBuilder queryBldr = new QueryBuilder(Type.get(DBPropertiesUpdate.TYPE_PROPERTIES_LOCAL));
              queryBldr.addWhereAttrEqValue("PropertyID", _propertyid);
              queryBldr.addWhereAttrEqValue("LanguageID", getLanguageId(_language));
              final InstanceQuery query = queryBldr.getQuery();
              query.executeWithoutAccessCheck();
              if (query.next()) {
                  ret = query.getCurrentValue();
              }
          } catch (final EFapsException e) {
              DBPropertiesUpdate.LOG.error("getExistingLocale(String)", e);
          }
          return ret;
      }
docs: Is a localized value already existing.
  
  @param _propertyid   ID of the Property, the localized value is related to
  @param _language     Language of the property
  @return OID of the value, otherwise null