SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function toString (children 1)
     ExpressionList (children 1)
      Function arrayCompact (children 1)
       ExpressionList (children 1)
        Function arrayMap (children 1)
         ExpressionList (children 2)
          Function lambda (children 1)
           ExpressionList (children 2)
            Function tuple (children 1)
             ExpressionList (children 1)
              Identifier x
            Literal UInt64_0
          Literal Array_[NULL]