BL.Permiso.getPermisosUsuario C# (CSharp) Метод

        public List<string> getPermisosUsuario(string username)
        {
            try
            {
                List<string> pers = new List<string>();

                var usrQuery = from u in entidad.usuarios
                               where u.username == username
                               select u;

                DataAccess.usuario usrtmp = usrQuery.First();

                foreach (role rl in usrtmp.roles)
                {
                    foreach (permiso per in rl.permisos)
                    {
                        pers.Add(per.id);
                    }
                }

                return pers;
            }
            catch (Exception ex)
            {
                throw new Exception(ex.ToString() + " --Permiso.cs / getPermisosUsuario()");
            }
        }