anchor.diff:  -define(MAX_LISTINGS, 5).
   -define(MAX_BROKERS, 3).
   -define(TICKER_INTERVAL, 1000).
  +-define(MAX_RANDOM_SLEEP, 100).
   
   
   %%%----------------------------------------------------------------------------
  
positive.code: 
  %% Pick and return a random element from a given list
  choice(List) ->
      Maximum = length(List),
      Element = random:uniform(Maximum),
      lists:nth(Element, List).
  
negative.code:             {NewPortfolio, NewTransactions} = transaction(
                  choice([buy, sell]), Symbol, Price, 1, Portfolio, Transactions
              ),
              io:format("~p~n", [Prices]),
              io:format("~p~n", [dict:to_list(NewPortfolio)]),
              io:format("~p~n", [NewTransactions]),
              io:format("~n"),
  