BodyWriter.FlushAsync(cancellationToken).
addActionListener((e) -> { System.out.println("Light, Camera, Action !
return ` ${escapeHtml(documentName)} ${EXPORT_STYLES} ${body} `; 严格 CSP 明确拒绝默认外部资源，只允许 Data URL 图片、Data URL 字体和内联样式。
Behavioral and Brain Sciences.Wikipedia: https://en.