public function create($subjectOrName)
    {
        // Check if container or name is defined
        if (
            !$subjectOrName instanceof ContentSubjectInterface &&
            !(is_string($subjectOrName) && 0 < strlen($subjectOrName))
        ) {
            throw new InvalidOperationException("Excepted instance of ContentSubjectInterface or string.");
        }

        // New instance
        $content = $this->editor->getRepository()->createContent();

        // Create default container
        $this->editor->getContainerManager()->create($content);

        // Add to container if available
        if ($subjectOrName instanceof ContentSubjectInterface) {
            $subjectOrName->setContent($content);
        } else {
            $content->setName($subjectOrName);
        }

        return $content;
    }