hlsQualitySelector = function (options) {
  this.ready(() => {
    onPlayerReady(this, videojs.mergeOptions(defaults, options));
  });
}
A video.js plugin.

In the plugin function, the value of `this` is a video.js `Player`
instance. You cannot rely on the player being in a "ready" state here,
depending on how the plugin is invoked. This may or may not be important
to you; if not, remove the wait for "ready"!

@function hlsQualitySelector
@param    {Object} [options={}]
          An object of options left to the plugin author to define.