anchor.diff:  
       Time = timer:now_diff(T2, T1),
       TimeInSecs = Time / 1000000,
  -    io:format("Time elapsed: ~p. Time per iteration: ~p s~n", [TimeInSecs, TimeInSecs / Steps]).
  +    io:format("Time elapsed: ~p. Time per iteration: ~p s~n",
  +              [TimeInSecs, TimeInSecs / Steps]).
   
   -spec create_ants(pos_integer(), dimension(), dimension()) -> [ant()].
   create_ants(PopulationSize, Width, Height) ->
  
positive.code:     Seed = erlang:now(),
      test(Model, Seed, 50, 30, 5, 500).
  
  -spec test(model(), any(), dimension(), dimension(), pos_integer(), pos_integer()) -> ok.
  test(Model, Seed, Width, Height, NAnts, Steps) ->
      io:format("ListBased:~n"),
      random:seed(Seed),
      start(Model, list_based, Width, Height, NAnts, Steps),
      io:format("Gb_treeBased:~n"),
      random:seed(Seed),
      start(Model, gbtree_based, Width, Height, NAnts, Steps).
  
  -spec start(model(), world_impl(), dimension(), dimension(), pos_integer()) -> ok.
  start(Model, Impl, Width, Height, Steps) ->
      start(Model, Impl, Width, Height, 1, Steps).
  
  -spec start(model(), world_impl(), dimension(), dimension(), pos_integer(), pos_integer()) -> ok.
  start(Model, Impl, Width, Height, PopulationSize, Steps) ->
      Board = create_board(Impl, Width, Height),
      Ants = create_ants(Impl, PopulationSize, Width, Height),
  
      Env = #env{agents = Ants, world = Board, backend = Impl},
  
      Log = true,
      Animate = true,
  
      logger:start(Model, Env, Log, Animate),
  
negative.code: %%%-------------------------------------------------------------------
  -module(parallant).
  %% API
  -export([test/0, test/1, test/4, start/5, start/7]).
  -export([get_cell/3, update_board/3, move_ants/4, update_cell/1]).
  
  -include("parallant.hrl").
  