@Pure
	public Iterable<BusHub> busHubs() {
		final MultiCollection<BusHub> col = new MultiCollection<>();
		col.addCollection(this.validBusHubs);
		col.addCollection(this.invalidBusHubs);
		return Collections.unmodifiableCollection(col);
	}
@ Pure public Iterable < BusHub > busHubs ( ) { final MultiCollection < BusHub > col = new MultiCollection < > ( ) ; col . addCollection ( this . validBusHubs ) ; col . addCollection ( this . invalidBusHubs ) ; return Collections . unmodifiableCollection ( col ) ; }
Replies the list of the bus hubs of the bus network.

@return a list of bus hubs