se.cfs_rq may return group cfs_rq, not the top cfs_rq

https://github.com/iovisor/bcc/blob/e42ac4176998a6dcf0dbf3b6befeaad0a69cb98a/tools/runqlen.py#L149

When task group used, the se.cfs_rq returned is the group cfs_rq, not the cpu top cfs_rq, so the runqlen is just the number of tasks of that cgroup on the cpu.
Is there a way to get runqlen of the top cfs_rq?

Thanks.

Start at tools/runqlen.py line 149 and inspect how se.cfs_rq is obtained when task groups are enabled. Trace the relevant cfs_rq relationship in the Linux scheduler and determine how the top CPU cfs_rq can be identified. Done means runqlen reports the CPU's top cfs_rq rather than only the task group's count.

Written by the indexing model from the issue text.