如何使用monolog处理程序在Rollbar中进行分组？

I am using Monolog handler in Yii framework to capture errors in Rollbar. Now I need to introduce grouping feature in Rollbar to my code. Since I am using Monolog, I cannot do it by passing the parameter. Instead I need to search some other way. Interested in getting some help from you all guys.

Thanks in Advance.