Z-Order маркеров при кластеризации

function initMap() { 
  const point = {lat: 49.985, lng: 36.23}; 
  const map = new google.maps.Map(document.getElementById('map'), { 
    zoom: 14, 
    center: point 
  }); 
   
  const markers = []; 
  const points = [point, point, point]; 
  for (let i = 0; i < points.length; i++) { 
    const marker = new google.maps.Marker({ 
      position: points[i] 
    }); 
    markers.push(marker); 
  }; 
   
  const markerCluster = new MarkerClusterer(map, markers, { 
    imagePath: 'https://github.com/googlemaps/js-marker-clusterer/raw/gh-pages/images/m' 
  }); 
 
  const res = new google.maps.Marker({ 
    map: map, 
    position: point, 
    icon: { 
      path: google.maps.SymbolPath.FORWARD_CLOSED_ARROW, 
      fillColor: "green", 
      fillOpacity: 1, 
      scale: 7, 
      strokeWeight: 1, 
    }, 
    zIndex: 100 
  }); 
}

#map { 
  height: 400px; 
  width: 400px; 
  background-color: grey; 
}

<script src="https://github.com/googlemaps/js-marker-clusterer/raw/gh-pages/src/markerclusterer.js"></script> 
<script async defer src="https://maps.googleapis.com/maps/api/js?callback=initMap"></script> 
<div id="map"></div>