GetService(typeof(SVsExtensionManager)) as IVsExtensionManager returns null

Hi,

I have attached sample program below

https://1drv.ms/u/s!ArdounX--7yPphSK9MPF8KkiYyFl

GetService(typeof(SVsExtensionManager)) as IVsExtensionManager; always returns null

I am using VS2015 enterprise IDE. I wants to enable/disable the visual studio extension. So I wants to use above code.

Kindly suggest anybody how to get service of SVsExtensionManager.

Thanks, Bharathraj