outgoingMessage.getHeader(name)

• name <string> 标题名称
• 返回：<number> | <string> | <string[]> | <undefined>

获取指定名称的 HTTP 头的值。如果该头未设置，返回的值将是 undefined。

🌐 Gets the value of the HTTP header with the given name. If that header is not set, the returned value will be undefined.