Test suite for PL/pgSQLScenario:    A building with a modern TP cabel installation where any    of the wall connectors can be used to plug in phones,    ethernet interfaces or local office hubs. The backside    of the wall connectors is wired to one of several patch-    fields in the building.    In the patchfields, there are hubs and all the slots    representing the wall connectors. In addition there are    slots that can represent a phone line from the central    phone system.    Triggers ensure consistency of the patching information.    Functions are used to build up powerful views that let    you look behind the wall when looking at a patchfield    or into a room.