module RecursiveRecord
  use mach.java.util.NoSuchElementException
  use mach.java.util.Optional


  type t = {
    a : bool;
    next : optional t
  }

  let get_next (self : t) : t
    ensures { self.next = Optional.build result } 
    raises { NoSuchElementException.E -> not is_present self.next } 
  =
    Optional.get self.next

  let default_cstr [@java:constructor]() = { a = false; next = empty () }

end