lib/engine.js
function createChoiceListener(li, index) {
  li.clickListener = choiceListener(index);
  li.addEventListener('click', li.clickListener);
  li.clearListener = (function () {
    this.removeEventListener('click', this.clickListener);
  }).bind(li);
}
function createChoiceListener(li, index) {
  li.clickListener = choiceListener(index);
  li.addEventListener('click', li.clickListener);
  li.clearListener = (function () {
    this.removeEventListener('click', this.clickListener);
  }).bind(li);
}
function createChoiceListener ( li , index ) { li . clickListener = choiceListener ( index ) ; li . addEventListener ( 'click' , li . clickListener ) ; li . clearListener = ( function ( ) { this . removeEventListener ( 'click' , this . clickListener ) ; } ) . bind ( li ) ; }
Attach that listener to the element.
Attach that listener to the element .