code: function(t) {
              var tce = null;
              if (t instanceof CustomEvent) {
                  tce = t;
              } else if (Overlay._TRIGGER_MAP[t]) {
                  tce = Overlay._TRIGGER_MAP[t];
              }
              return tce;
          }
docs: Helper method to locate the custom event instance for the event name string
  passed in. As a convenience measure, any custom events passed in are returned.
  
  @method _findTriggerCE
  @private
  
  @param {String|CustomEvent} t Either a CustomEvent, or event type (e.g. "windowScroll") for which a
  custom event instance needs to be looked up from the Overlay._TRIGGER_MAP.