title: getClusters() always returning an empty array (Using MarkerClustererPlus for Google Maps V3)
body: <p>I have the following code that loads a map and clusters the markers:</p>
  
  <pre><code>$scope.getMapHistory = function(locations){
  
      var map = new google.maps.Map(document.getElementById('map-canvas-history'), {
        zoom: 17,
        center: google.maps.LatLng(0, 0)
      });
  
      var markers = [];
      locations.forEach(function(deviceLocation){
        //var dataPhoto = data.photos[i];
        var devLat = deviceLocation._source.data.location[1];
        var devLng = deviceLocation._source.data.location[0];
        var latLng = new google.maps.LatLng(devLat, devLng);
        var marker = new google.maps.Marker({position: latLng });
        markers.push(marker);
      });
  
      var markerCluster = new MarkerClusterer(map, markers);
  
      //Test to get the clusters
      console.log(markerCluster);
      console.log(markerCluster.getClusters());
      console.log(markerCluster.getTotalClusters());
  
      markerCluster.fitMapToMarkers();
  
      $scope.hideLoading('loadingMap'); //Hides the loading gif
  
  }
  </code></pre>
  
  <p>Until there everything is ok. The problem is that I want to access the clusters array and when I try to log the return of <code>markerCluster.getClusters()</code>, it returns a empty array. Also, <code>.getTotalClusters()</code> is returning 0.</p>
  
  <p><img src="https://i.stack.imgur.com/Qi1Ne.png" alt="enter image description here"></p>
  
  <p>However when I log the whole <code>markerCluster</code> and open it on the console I can see the clusters_ array:</p>
  
  <p><img src="https://i.stack.imgur.com/yWkvD.png" alt="enter image description here"></p>
  
  <p>The markers clustering works fine, but I cannot access the array of cluster nor the number of clusters. Does someone know what might be happening?
  (I can give more details if my explanation isn't enough)</p>