protected function validateUser(User $user, $teamId)
    {
        if ($user->hasMemberOnTeam($teamId)) {
            $validationException = ValidationException::withMessages(['email' => 'EMAIL_HAS_TEAM_EMPLOYEE']);
            throw $validationException;
        }
        if ($user->hasMemberInvitationOnTeam($teamId)) {
            $validationException = ValidationException::withMessages(['email' => 'EMAIL_HAS_TEAM_EMPLOYEE_INVITATION']);
            throw $validationException;
        }
        return $user;
    }