anchor.diff:                           function(),
                            {lasp_vertex(), function()}}.
   
  --record(vertex_label, {pointer_pid :: pid()}).
  +-record(vertex_label, {process_pointer :: contract_process_id()}).
   
   -type lasp_vertex() :: id() | pid().
   
  
positive.code: apply_sequentially(X, [], _, Final) -> Final(X);
  apply_sequentially(X, [H | T], Int, Final) ->
      apply_sequentially(Int(H(X)), T, Int, Final).
  
  %%%===================================================================
  %%% .DOT export functions
  
negative.code:         _ ->
              St0#state{contraction_step = CtStep + 1}
      end,
      {reply, R, St#state{optimized_map = NewOptMap, pid_table = NewPidTable}}.
  
  %% @private
  -spec handle_cast(term(), #state{}) -> {noreply, #state{}}.
  