public void addNonFinalCandidate(String alias, ExprNodeDesc expr) {
    if (nonFinalPreds.get(alias) == null) {
      nonFinalPreds.put(alias, new ArrayList<ExprNodeDesc>());
    }
    nonFinalPreds.get(alias).add(expr);
  }
Adds the specified expr as a non-final candidate

@param expr
ql/src/java/org/apache/hadoop/hive/ql/ppd/ExprWalkerInfo.java