[I7] How to apply open all to a group of items

I have a question about ALL which is puzzling me. I have a room with a number of individual lockers in it. Each single locker is working fine. I’ve created a kind of container for the locker, so I can refer to all of them

A locker is a kind of container

What I’m struggling with is how to code for inputs such as EXAMINE ALL THE LOCKERS, OPEN ALL THE LOCKERS etc. I think I’m asking how do I apply ALL to my lockers?

The possibility to use all is set for a certain command rather than for a certain kind of object.

Understand "open [things]" as opening. makes the game understand OPEN ALL LOCKERS, OPEN ALL DOORS, OPEN ALL, etc.

It will still process the actions one at a time, though. If you need to react to a multiple-object differently – that is, if “OPEN ALL” needs to be different from “OPEN LOCKER 1. OPEN LOCKER 2” – look at chapter 20.6.

It may also be sufficient to create a scenery “lockers” object, and give that a special description.

Didn’t someone make an extension for examine all? Jon Ingold, I think?