Where do I place my mashape API key in Node application...?

var EventEmitter = require("events").EventEmitter;
var https = require("https");
var http = require("http");
var util = require("util");

/**
* An EventEmitter to get actor's Netflix info
* @param actor
* @constructor
*/
function Actor(actor) {

  EventEmitter.call(this);

  actorEmitter = this;

//  setRequestHeader("X-Mashape-Authorization", "API KEY HERE");

  var request = https.get("https://community-netflix-roulette.p.mashape.com/api.php?actor=" + actor.replace(/\s/ig, "%20"), function(response) {
    var body = "";

    if (response.statusCode !== 200) {
      request.abort();
      actorEmitter.emit("error", new Error("There was an error getting the actor/actress' info for " + actor + ". (" + http.STATUS_CODES[response.statusCode] + ")"));
    }

    response.on('data', function(chunk) {
      body += chunk;
      actorEmitter.emit("data", chunk);
    });

    response.on("end", function() {
      if (response.statusCode === 200) {
        try {
          var actor = JSON.parse(body);
          actorEmitter.emit("end", actor);
        } catch (error) {
          actorEmitter.emit("error", error);
        }
      }
    }).on("error", function(error) {
      actorEmitter.emit("error", error);
    });
  });
util.inherits(Actor, EventEmitter);
module.exports = Actor;