Neos\Neos\Controller\Module\Management\WorkspacesController::discardWorkspaceAction PHP Method

    public function discardWorkspaceAction(Workspace $workspace)
    {
        $unpublishedNodes = $this->publishingService->getUnpublishedNodes($workspace);
        $this->publishingService->discardNodes($unpublishedNodes);
        $this->addFlashMessage($this->translator->translateById('workspaces.allChangesInWorkspaceHaveBeenDiscarded', [htmlspecialchars($workspace->getTitle())], null, null, 'Modules', 'Neos.Neos'));
        $this->redirect('index');
    }