anchor.diff:      Base - Diff.
   
   run(get, KeyGen, _ValueGen, #state{check_integrity = CI, id = Id, concurrent = Concurrent} = State) ->
  -    Key = keygen_global_uniq(CI, Id, Concurrent, KeyGen), 
  +    Key = keygen_global_uniq(CI, Id, Concurrent, KeyGen),
       {NextUrl, S2} = next_url(State),
       case do_get(url(NextUrl, Key, State#state.path_params)) of
           {not_found, _Url} ->
  
positive.code: 
  
  run(delete, KeyGen, _ValueGen, #state{check_integrity = CI, id = Id, concurrent = Concurrent} = State) ->
      Key = keygen_global_uniq(CI, Id, Concurrent, KeyGen), 
      {NextUrl, S2} = next_url(State),
      case do_delete(url(NextUrl, Key, State#state.path_params)) of
          {not_found, _Url} ->
  
negative.code: 
  
  run(put, KeyGen, ValueGen, #state{check_integrity = CI, id = Id, concurrent = Concurrent} = State) ->
      Key = keygen_global_uniq(CI, Id, Concurrent, KeyGen),
      Val = ValueGen(),
      {NextUrl, S2} = next_url(State),
      Url = url(NextUrl, Key, State#state.path_params),
  