function executeDispatchesInOrderStopAtTrueImpl(event) {
	  var dispatchListeners = event._dispatchListeners;
	  var dispatchInstances = event._dispatchInstances;
	  if (process.env.NODE_ENV !== 'production') {
	    validateEventDispatches(event);
	  }
	  if (Array.isArray(dispatchListeners)) {
	    for (var i = 0; i < dispatchListeners.length; i++) {
	      if (event.isPropagationStopped()) {
	        break;
	      }
	      // Listeners and Instances are two parallel arrays that are always in sync.
	      if (dispatchListeners[i](event, dispatchInstances[i])) {
	        return dispatchInstances[i];
	      }
	    }
	  } else if (dispatchListeners) {
	    if (dispatchListeners(event, dispatchInstances)) {
	      return dispatchInstances;
	    }
	  }
	  return null;
	}
Standard/simple iteration through an event's collected dispatches, but stops
at the first dispatch execution returning true, and returns that id.

@return {?string} id of the first dispatch execution who's listener returns
true, or null if no listener returned true.