src/bind.dom.js
function bind(element, eventName, callback) {
  element.addEventListener(eventName, callback);

  return function unbind() {
    element.removeEventListener(eventName, callback);
  };
}
function bind(element, eventName, callback) {
  element.addEventListener(eventName, callback);

  return function unbind() {
    element.removeEventListener(eventName, callback);
  };
}
function bind ( element , eventName , callback ) { element . addEventListener ( eventName , callback ) ; return function unbind ( ) { element . removeEventListener ( eventName , callback ) ; } ; }
bind - listens to event on element, returning a function to stop listening to the event.
@param {EventTarget} element - https://developer.mozilla.org/en-US/docs/Web/API/EventTarget
@param {String} eventName - Name of the event. Like 'click', or 'did-custom-event'
@param {Function} callback -
@return unbind - function that unbinds the callback from the event on element.
bind - listens to event on element returning a function to stop listening to the event .