|·||stagingLocations - The valid "staging locations" for this nested room. This is a list of the rooms from which an actor can DIRECTLY reach this nested room; in other words, the actor will be allowed to enter 'self', with no intervening travel, if the actor is directly in any of these locations. If the list is empty, there are no valid staging locations. The point of listing staging locations is to make certain that the actor has to go through one of these locations in order to get into this nested room. This ensures that we enforce any conditions or trigger any side effects of moving through the staging locations, so that a player can't bypass a puzzle by trying to move directly from one location to another without going through the required intermediate steps. Since we always require that an actor go through one of our staging locations in order to enter this nested room, and since we carry out the travel to the staging location using implied commands (which are just ordinary commands, entered and executed automatically by the parser), we can avoid having to code any checks redundantly in both the staging locations and any other nearby locations. By default, an actor can only enter a nested room from the room's direct container. For example, if a chair is on a stage, an actor must be standing on the stage before the actor can sit on the chair.