# Edges can have labels, too:
 [ Kempten ] -- Bahn --> [ Schongau ]			# normal edge
 [ Schongau ] -- Fahrrad --> [ Regensburg ]		# ditto
 [ Regensburg ] .. Auto ..> [ Roth ]			# dashed
 [ Regensburg ] == Motorradkolonne ==> [ Straubing ]	# double
