method OutgoingMessage.prototype.setHeaderOutgoingMessage.prototype.setHeader(name: string,value: number | string | readonly string[],): thisDeprecatedSets a single header value. If the header already exists in the to-be-sent headers, its value will be replaced. Use an array of strings to send multiple headers with the same name. Parametersname: stringHeader name value: number | string | readonly string[]Header value Return Typethis