let x =
   object
     val mutable x = 5
     method get_x = x
     method set_x y = x <- y
   end;;

let y =
   object
     method get_x = 2
     method set_x y = Printf.printf "%d\n" y
   end;;

let set_to_10 a = a#set_x 10;;

let z =
   object
     method blahblah = 2.5
     method set_x y = Printf.printf "%d\n" y
   end;;

type simpler_obj = < get_x : int >;;

let get_x a = a#get_x;;