SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function xxHash64 (children 1)
     ExpressionList (children 1)
      Function materialize (children 1)
       ExpressionList (children 1)
        Function array (children 1)
         ExpressionList (children 1)
          Function CAST (children 1)
           ExpressionList (children 2)
            Literal NULL
            Literal \'Nullable(String)\'
