node.js http agent with proxy

var HttpsProxyAgent = require('https-proxy-agent');
this.agent = new HttpsProxyAgent("http://example.proxy.com");

however i need to add a set node.js original agent setting as well.

http.Agent({ keepAlive: true });

I donot see an option with httpsproxyagent to set this, as https-proxy-agent is derived from agent-base. Is there a way to achieve this with a different node.js module?

via tx fun