private static boolean isSargsCacheEnabled(Configuration conf) {
    return HiveConf.getIntVar(conf, HiveConf.ConfVars.HIVE_IO_SARG_CACHE_MAX_WEIGHT_MB) > 0;
  }
Do the recursive parse of the Hive ExprNodeDesc into our ExpressionTree.
@param expression the Hive ExprNodeDesc
ql/src/java/org/apache/hadoop/hive/ql/io/sarg/ConvertAstToSearchArg.java