SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function concat (children 1)
     ExpressionList (children 2)
      Literal \'With \'
      Function materialize (children 1)
       ExpressionList (children 1)
        Function CAST (children 1)
         ExpressionList (children 2)
          Function map (children 1)
           ExpressionList (children 2)
            Literal UInt64_42
            Literal \'foo\'
          Literal \'Map(Int32, String)\'