EntityWorkspaceConflictConstraint.php

<?php

namespace Drupal\workspaces\Plugin\Validation\Constraint;

use Drupal\Core\StringTranslation\TranslatableMarkup;
use Drupal\Core\Validation\Attribute\Constraint;
use Symfony\Component\Validator\Constraint as SymfonyConstraint;

/**
 * Validation constraint for an entity being edited in multiple workspaces.
 */
class EntityWorkspaceConflictConstraint extends SymfonyConstraint {
    
    /**
     * The default violation message.
     *
     * @var string
     */
    public $message = 'The content is being edited in the @label workspace. As a result, your changes cannot be saved.';

}