Each user can only have one session at any given time. Multiple users logged into the same Admin GUI instance at once is okay but the same user cannot have multiple simultaneous sessions.
When a user logs in, perform a check to see if a session for that user currently exists
If session already exists, abort log in attempt and display “User is already logged in”
Log in as a user
Attempting to log in as the same user on a different browser results in the condition specified in the completion criteria
Attempting to log in as a different user is successful with no issues detected