# Different edge styles
 [ Bonn ] <-> [ Berlin ]  # bidirectional
 [ Berlin ] ==> [ Rostock ]  # double
 [ Hamburg ] ..> [ Altona ]  # dotted
 [ Dresden ] - > [ Bautzen ] # dashed
 [ Schweinfurt ] <=> [ Ulm ]      # bidrectional, double
 [ Magdeburg ] .-> [ Burg ]  # dot-dash
 [ Burg ] -- [ Wolfen ]         # single, bidirectional w/o arrows
 [ Wolfen ] .. [ Coswig ]       # dotted, bidirectional w/o arrows
 [ Magdeburg ] ..> [ Aue ]   # dotted, going downwards