anchor.diff:  %%                     {stop, Reason}
   %% @end
   %%--------------------------------------------------------------------
  -init(Host) ->
  +init(Host, Ref, From) ->
       process_flag(trap_exit, true),
       {ok, DB} = tachyon_backend:init(),
  +    From ! {Ref, {ok, self()}},
       loop(#state{db=DB, host = Host}).
   
   loop(State) ->
  
positive.code: -include("tachyon_statistics.hrl").
  
  %% API
  -export([init/1, put/5, stats/1, start/1]).
  -ignore_xref([start/1]).
  
  -define(SERVER, ?MODULE).
  
negative.code: %%--------------------------------------------------------------------
  
  start(Host) ->
      Ref = make_ref(),
      spawn(tachyon_guard, init, [Host, Ref, self()]),
      receive
          {Ref, R} ->
              R
      after 5000 ->
              {error, timeout}
      end.
  
  -ifdef(GUARD).
  put(Host, Time, Metric, Value, T) ->
  