GROUPING() function errors out due to case-sensitivity of function name

explain cbo select GROUPING(l_suppkey) from lineitem group by l_suppkey with rollup;
Error: Error while compiling statement: FAILED: SemanticException [Error 10015]: Line 1:19 Arguments length mismatch 'l_suppkey': grouping() requires at least 2 argument, got 1 (state=21000,code=10015)

explain cbo select grouping(l_suppkey) from lineitem group by l_suppkey with rollup;

+----------------------------------------------------+
|                      Explain                       |
+----------------------------------------------------+
| CBO PLAN:                                          |
| HiveProject(_o__c0=[grouping($1, 0:BIGINT)])       |
|   HiveAggregate(group=[{0}], groups=[[{0}, {}]], GROUPING__ID=[GROUPING__ID()]) |
|     HiveProject(l_suppkey=[$2])                    |
|       HiveTableScan(table=[[tpch, lineitem]], table:alias=[lineitem]) |
|                                                    |
+----------------------------------------------------+

 @Override
      public Object post(Object t) {
         ....
          if (func.getText().equals("grouping") && func.getChildCount() == 0) {