View a Space as a different users/group

Would like functionality that allows you to view a Space as if a specific user or in a specific group

In order to test out how a Space appears to different types of users I have to set up a test user and log onto the system using that user - possibly changing permissions in between.

This is causing issues when multiple Space admins want to test permission schemes and we don't want to spend all our admin time changing test user permissions!