SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function lambda (alias lambda) (children 1)
     ExpressionList (children 2)
      Function tuple (children 1)
       ExpressionList (children 1)
        Identifier x
      Function concat (children 1)
       ExpressionList (children 2)
        Function concat (children 1)
         ExpressionList (children 2)
          Function toString (children 1)
           ExpressionList (children 1)
            Identifier x.id
          Literal \'_\'
        Identifier x.value
   ExpressionList (children 2)
    Function CAST (alias value) (children 1)
     ExpressionList (children 2)
      Literal Tuple_(UInt64_1, \'Value\')
      Literal \'Tuple (id UInt64, value String)\'
    Function lambda (children 1)
     ExpressionList (children 1)
      Identifier value