anchor.diff:  get_link_should_return_target_from_memory(Config) ->
       [Worker | _] = ?config(cluster_worker_nodes, Config),
       ?assertMatch({{ok, #link{}}, _}, rpc:call(Worker,
  -        datastore_links_crud, apply, [?CTX, ?KEY, ?LINK_TREE_ID, add, [
  -            ?LINK_NAME, ?LINK_TARGET
  -        ]]
  -    )),
  -    {{ok, Link}, _} = ?assertMatch({{ok, #link{}}, _}, rpc:call(Worker,
  -        datastore_links_crud, apply, [?CTX, ?KEY, ?LINK_TREE_ID, get, [
  +        datastore_links_crud, apply, [?CTX(?KEY), ?KEY, ?LINK_TREE_ID, add, [
  +            ?LINK_NAME, ?LINK_TARGET
  +        ]]
  +    )),
  +    {{ok, Link}, _} = ?assertMatch({{ok, #link{}}, _}, rpc:call(Worker,
  +        datastore_links_crud, apply, [?CTX(?KEY), ?KEY, ?LINK_TREE_ID, get, [
               ?LINK_NAME
           ]]
       )),
  
positive.code: tree_fold_should_return_all_targets(Config) ->
      [Worker | _] = ?config(cluster_worker_nodes, Config),
      LinksNum = 1000,
      AllLinks = add_links(Worker, ?CTX, ?KEY, ?LINK_TREE_ID, LinksNum),
      Links = fold_links(Worker, ?CTX, ?KEY, #{}),
      ?assertEqual(get_expected_links(AllLinks), Links).
  
  tree_fold_should_return_targets_from_offset(Config) ->
      [Worker | _] = ?config(cluster_worker_nodes, Config),
      LinksNum = 1000,
      AllLinks = add_links(Worker, ?CTX, ?KEY, ?LINK_TREE_ID, LinksNum),
      lists:foreach(fun(Offset) ->
          Links = fold_links(Worker, ?CTX, ?KEY, #{offset => Offset}),
          ?assertEqual(get_expected_links(AllLinks, Offset), Links)
      end, lists:seq(0, LinksNum)).
  
  tree_fold_should_return_targets_from_link(Config) ->
      [Worker | _] = ?config(cluster_worker_nodes, Config),
      LinksNum = 1000,
      AllLinks = add_links(Worker, ?CTX, ?KEY, ?LINK_TREE_ID, LinksNum),
      Names = lists:map(fun(#link{name = Name}) -> Name end, AllLinks),
      lists:foreach(fun({Offset, Name}) ->
          Links = fold_links(Worker, ?CTX, ?KEY, #{
              prev_tree_id => ?LINK_TREE_ID,
              prev_link_name => Name
          }),
  
negative.code: delete_link_should_delete_link_on_disc(Config) ->
      [Worker | _] = ?config(cluster_worker_nodes, Config),
      ?assertMatch({{ok, #link{}}, _}, rpc:call(Worker,
          datastore_links_crud, apply, [?CTX(?KEY), ?KEY, ?LINK_TREE_ID, add, [
              ?LINK_NAME, ?LINK_TARGET
          ]]
      )),
      ?assertMatch({ok, _}, rpc:call(Worker,
          datastore_links_crud, apply, [?CTX(?KEY), ?KEY, ?LINK_TREE_ID, delete, [
              ?LINK_NAME
          ]]
      )).
  