extensions/markdown-language-features/src/preview/preview.ts/DynamicMarkdownPreview/_getPreviewTitle
class DynamicMarkdownPreview:	private static _getPreviewTitle(resource: vscode.Uri, locked: boolean): string {
		const resourceLabel = uri.Utils.basename(resource);
		return locked
			? vscode.l10n.t('[Preview] {0}', resourceLabel)
			: vscode.l10n.t('Preview {0}', resourceLabel);
	}