Concept
Premeditatio Malorum
3 books in the library reach for this idea - each in its own way. When independent authors converge on one concept, it usually deserves attention.
Letters from a Stoic
How this book uses it: Rehearse worst-case scenarios to reduce anxiety. Before important events, visualize failure - you'll handle it.
Meditations
How this book uses it: Negative visualization - imagine worst-case scenarios not to be pessimistic but to be prepared and grateful.
The Daily Stoic
How this book uses it: Mentally rehearse worst-case scenarios not to be pessimistic but to be prepared and grateful for what you have.