OOP - How does one create a class in ReasonML

I know that in OCaml, one can create a class doing the following:

class stack_of_ints =
  object (self)
    val mutable the_list = ( [] : int list ) (* instance variable *)
    method push x =                        (* push method *)
      the_list <- x :: the_list
  end;;

However, I have been struggling on finding documentation on how to do it in Reason. Thank you.