Add httpOptions option

README.md

@@ -446,7 +446,8 @@ The default values are shown after each option key.
     compress: true,         // support gzip/deflate content encoding. false to disable
     size: 0,                // maximum response body size in bytes. 0 to disable
     agent: null,            // http(s).Agent instance or function that returns an instance (see below)
-    highWaterMark: 16384    // the maximum number of bytes to store in the internal buffer before ceasing to read from the underlying resource.
+	highWaterMark: 16384,    // the maximum number of bytes to store in the internal buffer before ceasing to read from the underlying resource.
+	extraHTTPOptions: {}	// additional options to include in http(s).request options that cannot be configured by the http(s).Agent override.
 }
 ```
 
@@ -537,6 +538,13 @@ const fetch = require('node-fetch');
 })();
 ```
 
+
+#### Extra HTTP Options
+
+Extra options to pass to http.request.
+See [`http.request`](https://nodejs.org/api/http.html#http_http_request_url_options_callback) for more information.
+
+
 <a id="class-request"></a>
 
 ### Class: Request

src/request.js

@@ -100,6 +100,7 @@ export default class Request extends Body {
 		this.counter = init.counter || input.counter || 0;
 		this.agent = init.agent || input.agent;
 		this.highWaterMark = init.highWaterMark || input.highWaterMark || 16384;
+		this.extraHTTPOptions = init.extraHTTPOptions || input.extraHTTPOptions || {};
 	}
 
 	get method() {
@@ -203,6 +204,7 @@ export const getNodeRequestOptions = request => {
 
 	// Manually spread the URL object instead of spread syntax
 	const requestOptions = {
+		...request.extraHTTPOptions,
 		path: parsedURL.pathname + search,
 		pathname: parsedURL.pathname,
 		hostname: parsedURL.hostname,