public ExprNodeGenericFuncDesc build() throws Exception {
      if (stack.size() != 1) {
        throw new Exception("Bad test: " + stack.size());
      }
      return (ExprNodeGenericFuncDesc)stack.pop();
    }
Helper class for building an expression.
ql/src/test/org/apache/hadoop/hive/metastore/TestMetastoreExpr.java