SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function in (children 1)
     ExpressionList (children 2)
      Function tuple (children 1)
       ExpressionList (children 2)
        Function CAST (children 1)
         ExpressionList (children 2)
          Literal NULL
          Literal \'Nullable(String)\'
        Literal UInt64_42
      Subquery (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 2)
           Literal \'abc\'
           Literal UInt64_42
