What would AggrefExprState nodes' args contain?

Hello all,<br /><br />While examining the executor, I was wondering what the *args part of AggrefExprState nodes
contain.I found that the Aggref (Expr)'s  args list is a list of TargetEntry nodes. But the state node's args is
initializedin ExecInitExpr as:<br /><br />astate->args = (List *) ExecInitExpr((Expr *) aggref->args,<br />   
                                                    parent);<br /><br />This would mean that the args is actually a
ExprStatenode list with one single item (the ExprState node / tree). I believe it potentially contains the execution
treeto determine the state / value of the aggref (sub)expression. But then in the ExecEvalAggref function I do not see
theargs coming into picture at all! I am also unable to find a call to some function for executing the state node
createdin the args list. Also, no value is being extracted from that node! Why is it so? <br /><br />For quick
referenceI am adding the function (may be you don't need it but still... its a small one):<br /><br />/*
----------------------------------------------------------------<br/> *        ExecEvalAggref<br /> *<br />  *       
Returnsa Datum whose value is the value of the precomputed<br /> *        aggregate found in the given expression
context.<br/> * ----------------------------------------------------------------<br /> */<br />static Datum<br />
ExecEvalAggref(AggrefExprState*aggref, ExprContext *econtext,<br />               bool *isNull, ExprDoneCond
*isDone)<br/>{<br />   if (isDone)<br />        *isDone = ExprSingleResult;<br /><br />    if
(econtext->ecxt_aggvalues== NULL)        /* safety check */<br />         elog(ERROR, "no aggregates in this
expressioncontext");<br /><br />    *isNull = econtext->ecxt_aggnulls[aggref->aggno];<br />    return
econtext->ecxt_aggvalues[aggref->aggno];<br/>}<br /><br /><br />What is the use of args in AggrefExprState node
here?Is it there just for some historical reason?<br /><br />Regards,<br />Vaibhav <br />