PropertyCollector.RetrievePropertiesEx instead of VcVirtualMachine.recentTask

I would like to get results of VcVirtualMachine.recentTask, but according the documentation it is not working anymore:

In releases after vSphere API 5.0, vSphere Servers might not generate property collector update notifications for this property. To obtain the latest value of the property, you can use PropertyCollector methods RetrievePropertiesEx or WaitForUpdatesEx.

I haven't found any example using it and the documentation didn't really helped me to understand how to use it.

Could somebody point me to the right direction?

maaca