anchor.diff:  update_with(Conn, DocId, Fun, Options) ->
     barrel_httpc:update_with(Conn, DocId, Fun, Options).
   
  +%% @doc Apply the specified updates to the database.
  +%% Note: The batch is not guaranteed to be atomic, atomicity is only guaranteed at the doc level.
  +-spec write_batch(Conn, Updates, Options) -> Results when
  +  Conn :: conn(),
  +  Updates :: [barrel_httpc:batch_op()],
  +  Options :: barrel_httpc:batch_options(),
  +  Results :: barrel_httpc:batch_results().
  +write_batch(Conn, Updates, Options) ->
  +  barrel_httpc:write_batch(Conn, Updates, Options).
  +
  +
   %% @doc fold all docs by Id
   -spec fold_by_id(Conn, Fun, AccIn, Options) -> AccOut | Error when
     Conn::conn(),
  
positive.code: get(Conn, DocId, Options) ->
    barrel_httpc:get(Conn, DocId, Options).
  
  %% @doc create or update a document. Return the new created revision
  %% with the docid or a conflict.
  -spec put(Conn, Doc, Options) -> Res when
  
negative.code:   database_infos/1,
    connect/1,
    get/3,
    multi_get/5,
    put/3,
    put/4,
    post/3,
    post/4,
    delete/3,
    update_with/4,
    write_batch/3,
    fold_by_id/4,
    fold_by_path/5,
    changes_since/5
  