SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function format (children 1)
     ExpressionList (children 3)
      Literal \'{{}}\'
      Function materialize (children 1)
       ExpressionList (children 1)
        Literal \'first\'
      Literal \'second\'