code: function (listeners, eventType, callback, after) {
                  var listArray = listeners[eventType] || [];
                  if (!ariaUtilsType.isArray(listArray)) {
                      listArray = [listArray];
                  }
  
                  if (after) {
                      listArray.push(callback);
                  } else {
                      listArray.splice(0, 0, callback);
                  }
                  listeners[eventType] = listArray;
              }
docs: Add a listener for an event. It will be called before an already registered event, if any.
  @protected
  @param {aria.html.beans.ElementCfg:Properties.on} listeners Map of listeners
  @param {String} eventType Type of the event
  @param {aria.core.CfgBeans:Callback} callback listener to chain
  @param {Boolean} after True if the listener has to be executed after all the other listeners. Otherwise,
  it will be executed before