title: Remove a particular marker in google map clustering in iOS
body: <p>I am using GMUClusterItem in my google map to load items.</p>
  
  <p>I can load the items using the below code (its a sample)</p>
  
  <pre><code>  let item = POIItem(position: CLLocationCoordinate2DMake(38.6646184, -120.9465773, name: "")           
    clusterManager.add(item)
  </code></pre>
  
  <p>It works fine</p>
  
  <p>But my problem is to remove a particular item.</p>
  
  <p>I tried the below code</p>
  
  <pre><code>  let item = POIItem(position: CLLocationCoordinate2DMake(38.6646184, -120.9465773), name: "")
    clusterManager.remove(item)
  </code></pre>
  
  <p>But its not working</p>
  
  <p>Is there mistake in that? If so, please help me to remove particular item.</p>
  
  <p>Thanks</p>