accessing an object property in node async

index.js

const async = require('async');

function myObject (text) {
  this.text = text;
}

myObject.prototype.run = function (callback) {
  async.parallel(
    [
      this.doing,
      this.doing,
      this.doing,  
    ],
    this.done
  );
}

myObject.prototype.doing = function (callback) {
  callback(null, "hello")
}

myObject.prototype.done = function (err, results) {
  console.log(results); // [ 'hello', 'hello', 'hello' ]
  console.log(this.text); // undefined
}

myObj = new myObject("world");
myObj.run();

package.json

{
  "name": "ba0fcc5c2ccc7a12cce419a87837065f",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "dependencies": {
    "async": "^2.6.0"
  },
  "devDependencies": {},
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "repository": {
    "type": "git",
    "url": "git+ssh://[email protected]/ba0fcc5c2ccc7a12cce419a87837065f.git"
  },
  "author": "",
  "license": "ISC",
  "bugs": {
    "url": "https://gist.github.com/ba0fcc5c2ccc7a12cce419a87837065f"
  },
  "homepage": "https://gist.github.com/ba0fcc5c2ccc7a12cce419a87837065f"
}