Why the user can not set `requiresOrder` and `requiresOver` in the `SqlUserDefinedAggFunction`

[jincheng sun]

Hi Julian，

 I have a question that need your help. The problem is described below:

 org.apache.calcite.sql.validate.SqlUserDefinedAggFunction calls the
constructor of SqlAggFunction:

Protected SqlAggFunction (

      String name,

      SqlIdentifier sqlIdentifier,

      SqlKind kind,

      SqlReturnTypeInference returnTypeInference,

      SqlOperandTypeInference operandTypeInference,

      SqlOperandTypeChecker operandTypeChecker,

      SqlFunctionCategory funcType,

      Boolean requiresOrder,

      Boolean requiresOver)

The requiresOrder = false, requiresOver = false. as follow:

Public SqlUserDefinedAggFunction (SqlIdentifier opName,

      SqlReturnTypeInference returnTypeInference,

      SqlOperandTypeInference operandTypeInference,

      SqlOperandTypeChecker operandTypeChecker, AggregateFunction function)
{

    Super (Util.last (opName.names), opName, SqlKind.OTHER_FUNCTION,

        ReturnTypeInference, operandTypeInference, operandTypeChecker,

        SqlFunctionCategory.USER_DEFINED_FUNCTION, false, false);

    This.function = function;

  }

I appreciated If you can tell me why the user can not set `requiresOrder`
and `requiresOver`  in the `SqlUserDefinedAggFunction` ?

Best,
SunJincheng