title: Getting markerclusterer clusters
body: <p>I am making a map with clusters and I want to show a list of clusters under it.</p>
  
  <p>To get clusters, I tried to retrieve them from the object. But it doesn't work as I expected:</p>
  
  <pre><code>    // Initialize clusterer
      markerCluster = new MarkerClusterer(map, markers, clusterOptions);
  
      // this logs an empty array
      var clusters = markerCluster.clusters_;
      console.log(clusters);
  
      // This logs array of clusters 
      setTimeout(function(){
          var clusters = markerCluster.clusters_;
          console.log(clusters);
      }, 500)
  </code></pre>
  
  <p>So I'm trying to figure out if there's an onload event or a callback function..</p>