// get all files for given user
        public HttpResponseMessage GetUserFiles(Guid userId, Guid playlistId)
        {
            HttpResponseMessage response;

            List <CFileInfo> filesInfo = new List <CFileInfo>();

            try
            {
                List <CFile> files = _fileContext.GetByPlaylistId(playlistId).ToList();

                foreach (CFile file in files)
                {
                    // do not return to user files that are not fully loaded
                    if (file.Hash != null)
                    {
                        CFileInfo fileInfo = file.ToCFileInfo();
                        filesInfo.Add(fileInfo);
                    }
                }

                response = Request.CreateResponse(HttpStatusCode.OK, filesInfo);
                return(response);
            }
            catch (Exception e)// in case program crashes?
            {
                HttpContext.Current.Response.StatusCode = (Int32)HttpStatusCode.BadRequest;
                throw new ContextException(e.Message, e);
            }
        }