[Tempest]How to find out the test cases regarding the operations of DHCP port from non-admin users

This is a set of integration tests to be run against a live OpenStack cluster.

I am trying to investigate to Tempest. Now, I want to edit code to change the permission of non-admin user with operations regarding DHCP port.

As you know, currently, Tempest tests for the cases that Non-admin users can create/modify/delete one or more DHCP port. And in my case, I want to change Tempest to test that Non-admin users cannot creat/modify/delete DHCP port.

But I am a newbie in Tempest, and I don't know how to find the test cases in Tempest regarding permission of Non-user with operations of DHCP port.

About tempest code please refer here:
http://ift.tt/1FfhYkr

If you know, please teach me the way to do that . Thank you very much for your help.