anchor.diff:      Args = [Bucket, Key, UUID, RiakcPid, Options],
       gen_fsm:start_link(?MODULE, Args, []).
   
  -block_deleted(Pid, BlockID) ->
  -    gen_fsm:send_event(Pid, {block_deleted, BlockID, self()}).
  +-spec block_deleted(pid(), {ok, integer()} | {error, binary()}) -> ok.
  +block_deleted(Pid, Response) ->
  +    gen_fsm:send_event(Pid, {block_deleted, Response, self()}).
   
   %% ====================================================================
   %% gen_fsm callbacks
  
positive.code:                                        delete_blocks_remaining=BlocksToDelete,
                                         timer_ref=TRef}}.
  
  deleting({block_deleted, BlockID, DeleterPid},
      State=#state{manifest=Manifest,
                   free_deleters=FreeDeleters,
                   unacked_deletes=UnackedDeletes}) ->
  
negative.code:             %% maybe start more deletes
              State3 = maybe_delete_block(State2),
              {next_state, deleting, State3}
      end;
  deleting({block_deleted, {error, Error}, _DeleterPid},
      State=#state{manifest=_Manifest,
                   timer_ref=TRef}) ->
      timer:cancel(TRef),
      %% TODO:
      %% sync manifest one last time
      {stop, Error, State}.
  
  handle_event(_Event, StateName, State) ->
      {next_state, StateName, State}.
  