SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function toTypeName (alias x) (children 1)
     ExpressionList (children 1)
      Function sum (children 1)
       ExpressionList (children 1)
        Function in (children 1)
         ExpressionList (children 2)
          Function toFixedString (children 1)
           ExpressionList (children 2)
            Literal \'a\'
            Function toLowCardinality (children 1)
             ExpressionList (children 1)
              Function toNullable (children 1)
               ExpressionList (children 1)
                Literal UInt64_1
          Function toFixedString (children 1)
           ExpressionList (children 2)
            Literal \'a\'
            Literal UInt64_1
