extensions/markdown-language-features/src/features/preview.ts/DynamicMarkdownPreview/getPreviewTitle
class DynamicMarkdownPreview:	private static getPreviewTitle(resource: vscode.Uri, locked: boolean): string {
		return locked
			? localize('lockedPreviewTitle', '[Preview] {0}', path.basename(resource.fsPath))
			: localize('previewTitle', 'Preview {0}', path.basename(resource.fsPath));
	}