anchor.diff:  -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
            terminate/2, code_change/3]).
   
  +-export([add_device/1]).
  +
   -define(SERVER, ?MODULE).
   
   -record(syn, { element:: report | config | mt_report | mt_dropped }).
  
positive.code: handle_call({ get_devices }, _From, State) ->
      get_devices(State);
  
  
  handle_call({ get_devices, CapKey }, _From, State) ->
      get_devices(State, CapKey);
  
  handle_call({ get_devices, CapKey, CapSpec }, _From, State) ->
      get_devices(State, CapKey, CapSpec);
  
  
  %%--------------------------------------------------------------------
  
negative.code: %%%===================================================================
  %%% Internal functions
  %%%===================================================================
  
  add_device(FileName) ->
      gen_server:call(?SERVER, { add_device, FileName }).
  
  convert_return_value(Bits) ->
      if Bits =:= ?IEDRV_RES_OK -> ok;
  