public void putAll(Map<ASTNode, String> exprToColumnAlias) throws SemanticException {
    for (ASTNode astNode : exprToColumnAlias.keySet()) {
      if (getExpression(astNode) != null) {
        put("", exprToColumnAlias.get(astNode), getExpression(astNode));
      }
    }
  }
Puts a resolver entry corresponding to the expression and its
column alias which is used for alias recognition in the latter constructs
@param exprToColumnAlias
         The map containing the expression to alias mapping
@throws SemanticException
ql/src/java/org/apache/hadoop/hive/ql/parse/RowResolver.java