node.js wd screenshot sample for parallel run (BrowserStack)

/*
 * require, fs, wd, assert, colors
 * saves screenshot in current folder as hello.png
 */

var fs = require('fs');

module.exports = function helloBrowserStack(browser, cb) {
  browser.get("http://www.google.com", function() {
    browser.title(function(err, title) {
      browser.elementByName('q', function(err, el) {
        el.sendKeys("BrowserStack", function() {
          browser.elementByName("btnG", function(err,el) {
            el.click(function() {
              browser.takeScreenshot(function(err, res){
                data = new Buffer(res, 'base64');
                fdr = fs.openSync("hello.png", 'w');
                fs.writeSync(fdr,data,0,data.length);
                browser.quit();
              })
            })
          })
        })
      })
    })
  })
};