code: function normalizeEvents(events)
  {
    // start with converting falsy events into catch-all placeholder
    events = events || entryPoint;
  
    if (!Array.isArray(events))
    {
      events = [events];
    }
  
    // return shallow copy
    return events.concat();
  }
docs: Normalizes provided events
  to keep `add` and `apply` on the same page
  
  @private
  @param   {null|string|array} events - events to normalize
  @returns {array} - normalized list of events