SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Function sum (alias s) (children 1)
     ExpressionList (children 1)
      Identifier a
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier order_with_aggr
   ExpressionList (children 1)
    OrderByElement (children 1)
     Identifier s
