Need an example for wait till element disappears with JS and WD

This is what I came up with eventually. Note that we need both setImplicitWaitTimeout and Q.delay

async function waitTillProgressBarDisappears(max_attempts=10){
      await driver.setImplicitWaitTimeout(MOCHA_IMPLICIT_TIMEOUT/10);
      let cond = await driver.hasElementByClassName('android.widget.ProgressBar');
      console.log(`element found -> ${cond}`)
      while(max_attempts > 0 && cond == true){
        await Q.delay(MODERATE_WAIT_TIME);
        console.log('attempts left', max_attempts)
        cond = await driver.hasElementByClassName('android.widget.ProgressBar');
        console.log(`element found inside -> ${cond}`)
        max_attempts--;
      }
      console.log(`existing with -> ${cond}`)
      await driver.setImplicitWaitTimeout(MOCHA_IMPLICIT_TIMEOUT);
    }