public bool Add(RefreshToken refreshToken) { var existingRefreshToken = _refreshTokenRepository .GetSingleByCondition(x => x.ClientId == refreshToken.ClientId && x.UserName == refreshToken.UserName); if (existingRefreshToken != null) { var resultRemove = _refreshTokenRepository.Delete(existingRefreshToken); if (resultRemove == null) { return(false); } } var entity = _refreshTokenRepository.Add(refreshToken); if (entity == null) { return(false); } _unitOfWork.Commit(); return(true); }