Craft\WorkflowController::actionRevokeSubmission PHP Method

    public function actionRevokeSubmission()
    {
        $submissionId = craft()->request->getParam('submissionId');
        $model = craft()->workflow_submissions->getById($submissionId);
        $model->status = Workflow_SubmissionModel::REVOKED;
        $model->dateRevoked = new DateTime();
        if (craft()->workflow_submissions->revokeSubmission($model)) {
            craft()->userSession->setNotice(Craft::t('Submission revoked.'));
        } else {
            craft()->userSession->setError(Craft::t('Could not revoke submission.'));
        }
        // Redirect page to the entry as its not a form submission
        craft()->request->redirect(craft()->request->urlReferrer);
    }