How to empty network HARLog in Chrome extension development?

I'm developing an extension for Chrome recently, I need to store the network HARLog, use api like this,

chrome.devtools.network.getHAR()

After, I hope to empty HARLog, so I thought out all the chrome.devtools.network api,

But I didn't find any api can do this job, so I inspect Chrome's Devtools Network tab, too.

chrome-devtools://devtools/bundled/network/network_module.js

There is the code how the network clear button realizing,

NetworkLog.networkLog.reset()

But when I use it in my code, there is an error: NetworkLog is undefined

Anyone can give some suggestions?

Thanks.