static Expression icebergDataFilterFromHiveConf(Configuration conf) {
    Expression icebergFilter = SerializationUtil.deserializeFromBase64(conf.get(InputFormatConfig.FILTER_EXPRESSION));
    if (icebergFilter != null) {
      // in case we already have it prepared..
      return icebergFilter;
    }
    String hiveFilter = conf.get(TableScanDesc.FILTER_EXPR_CONF_STR);
    if (hiveFilter != null) {
      ExprNodeGenericFuncDesc exprNodeDesc = SerializationUtilities
          .deserializeObject(hiveFilter, ExprNodeGenericFuncDesc.class);
      return getFilterExpr(conf, exprNodeDesc);
    }
    return null;
  }
Converts the Hive filter found in the job conf to an Iceberg filter expression.
@param conf - job conf
@return - Iceberg data filter expression
iceberg/iceberg-handler/src/main/java/org/apache/iceberg/mr/hive/HiveIcebergInputFormat.java