code: function _breadcrumbEventHandler(evtName) {
  	    var self = this;
  	    return function (evt) {
  	      // reset keypress timeout; e.g. triggering a 'click' after
  	      // a 'keypress' will reset the keypress debounce so that a new
  	      // set of keypresses can be recorded
  	      self._keypressTimeout = null; // It's possible this handler might trigger multiple times for the same
  	      // event (e.g. event propagation through node ancestors). Ignore if we've
  	      // already captured the event.
  
  	      if (self._lastCapturedEvent === evt) return;
  	      self._lastCapturedEvent = evt; // try/catch both:
  	      // - accessing evt.target (see getsentry/raven-js#838, #768)
  	      // - `htmlTreeAsString` because it's complex, and just accessing the DOM incorrectly
  	      //   can throw an exception in some circumstances.
  
  	      var target;
  
  	      try {
  	        target = htmlTreeAsString$1(evt.target);
  	      } catch (e) {
  	        target = '<unknown>';
  	      }
  
  	      self.captureBreadcrumb({
  	        category: 'ui.' + evtName,
  	        // e.g. ui.click, ui.input
  	        message: target
  	      });
  	    };
  	  }
docs: Wraps addEventListener to capture UI breadcrumbs
  @param evtName the event name (e.g. "click")
  @returns {Function}
  @private