Getting the test case count in Test Runner window

I remember using UnityEditor.Selection to get the Selected objects and its properties. This works only for the assets in the editor and the hierarchy. I have been wondering how to get the selected testcases information from the Test Runner window.

I am executing the test cases from the Test Runner window/panel for which I need to know how many test cases are selected. I have tried UnityEditor.Selection. But its always returning 0.

Any help would be appreciate.