AnyLogic how to set attractor choice to both free and random

Question

Is there a way to make attractor choice both free & random at the same time?

The problem I have with either on it's own is:

• When the choice is set to Free - agents are using attractors in very predictable order based on attractor creation.
• When the choice is set to Random - more than one agent is using an attractor at the same time, which I don't want.

Solution I found, but don't know how to implement correctly is in the following thread:

AnyLogic Attractor weird behavior

I tried to create an agent type (instead of a class) 'myAttractor' with a boolean variable inside (occupied or not occupied attractor), but I don't know how to assign that agent type to actual attractors within a node - if that is even possible?

Maybe there are other solutions to customise the attractor choice to achieve complete randomness with only one agent per attractor?

Many thanks in advance, Peter