SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function toTypeName (children 1)
     ExpressionList (children 1)
      Function randConstant (children 1)
       ExpressionList (children 1)
        Function CAST (children 1)
         ExpressionList (children 2)
          Literal UInt64_4
          Literal \'Nullable(UInt8)\'