anchor.diff:  -behaviour(gen_server).
   
   %% API
  --export([start_link/1, stop/0,
  -         request_lease/3, end_lease/2, get_leases/0]).
  +-export([start_link/1, stop/0
  +        ,request_lease/3, end_lease/2
  +        ,get_leases/0, clear_leases/0]).
   
   %% gen_server callbacks
   -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
  
positive.code: -spec get_leases() -> [#lease{}].
  get_leases() ->
      gen_server:call(?MODULE, {lease_req, get_leases}).
  
  
  %%%===================================================================
  
negative.code: handle_call({lease_req, get_leases}, _From, State) ->
      Reply = priv_get_leases(),
      lager:info("Request received: {get_leases} -> Reply: ~p"
                ,[Reply]),
      {reply, Reply, State};
  handle_call({lease_req, clear_leases}, _From, State) ->
      Reply = priv_clear_leases(),
      lager:info("Request received: {clear_leases} -> Reply: ~p"
                ,[Reply]),
      {reply, Reply, State};
  handle_call(_Request, _From, State) ->
  