title: Customize the marker on google map with clusters
body: <p>I am using google map SDK in my application and plotting marker on selected let long and for making groups on marker i am using GMUClusterManager for adding cluster on marker, but with this i am facing an issue to change the image of marker, with if i draw a marker with GMUClusterManager then there  no option to change marker image. So any one know any other way to make groups of all markers when user zoom in map, or to change the image of maker.</p>