RobotStudio event

How to use Energy API of RobotStudio SDK?

In my work ,I need to get energy consumption of ABB Robot through C#.The RobotStudio SDK has offered an Energy API ,shown in http://developercenter.robotstudio.com/blobproxy/devcenter/RobotStudio/html/2cd59b64-d43b-ab13-6979-f0b9084fe2bf.htm#!,but the API Reference is so simple that I don't know how to use it.And the offered code samples also don't show how to use it.can anyone tell me how to use the Energy API?