anchor.diff:                 end,
       Res = mongoc:transaction(Topology, Callback),
       do_delete_result(Res, to_map(permission, Rec), permission).
  -
  -
  -do_get_permission(#state{topology = Topology}, Query) ->
  -  Callback = fun(Conf) ->
  -                mongoc:find_one(Conf, ?COLLECTION_PERMISSIONS, Query, #{}, 0)
  -             end,
  -  Item = mongoc:transaction_query(Topology, Callback),
  -  do_get_result(Item, permission).
   
   do_get_permissions(#state{topology = Topology}, Query) ->
       Callback = fun(Conf) ->
  
positive.code:     {reply, do_create_permission(State, Rec), State};
  handle_call({delete_permission, Rec}, _From, State) ->
      {reply, do_delete_permission(State, Rec), State};
  handle_call({get_permission, Query}, _From, State) ->
      {reply, do_get_permission(State, Query), State};
  handle_call({get_permissions, Query}, _From, State) ->
    {reply, do_get_permissions(State, Query), State};
  
  
negative.code:     {reply, do_update_user(State, Rec), State};
  handle_call({delete_user, Rec}, _From, State) ->
      {reply, do_delete_user(State, Rec), State};
  handle_call({get_users}, _From, State) ->
      {reply, do_get_users(State), State};
  
  