anchor.diff:  request_event( Pid, Event ) ->
       { From, To } = from_to( self(), Pid ),
       Pid ! { { get_event,  Event }, From },
  -    wait_event( To ).
  +    wait( To ).
   
   -spec request_event_async( pid(), string() ) -> { ok, { pid(), reference() } }.
   request_event_async( Pid, Event ) ->
  
positive.code: start( Driver, Parameters ) ->
      { _, Tag } = From = from(),
      Pid = spawn( fun() -> enter_loop( Driver, Parameters, From ) end ),
      wait_start( { Pid, Tag } ).
  
  -spec start_link( binary(), [ binary() ] ) -> { ok, pid() } | { error, term() }.
  start_link( Driver, Parameters ) ->
      { _, Tag } = From = from(),
      Pid = spawn_link( fun() -> enter_loop( Driver, Parameters, From ) end ),
      wait_start( { Pid, Tag } ).
  
  -spec start_async( binary(), [ binary() ] ) -> { ok, { pid(), reference() } }.
  start_async( Driver, Parameters ) ->
  
negative.code: server_scenario_async_test_() ->
      { ok, From } = start_test_server_async( "echo.sh" ),
      { ok, Pid } = receive
          { Res1, From } -> Res1
      after
          ?DRIVER_TIMEOUT -> timeout
      end,
  