A Gardenvale lockout is usually an apartment door that self-closed behind someone taking the bins down, or a commuter home from the Sandringham line with the keys on an office desk. Opening it is not only about the lock: the door is often fire-rated, the building may run a master key, and the common entry has to be managed without leaving it propped for everyone.
True Locksmith works Gardenvale's handful of streets often enough to know the blocks, so the arrival time given on the phone is the one kept, with the right cylinders already on the van. How entry works is on the locked out recovery service
page; the Gardenvale locksmith page, Victoria, lists the rest.