code: public static void exports(Media media, Map<Circuit, Collection<TileRef>> circuits)
      {
          Check.notNull(media);
          Check.notNull(circuits);
  
          final Xml nodeCircuits = new Xml(NODE_CIRCUITS);
  
          for (final Map.Entry<Circuit, Collection<TileRef>> entry : circuits.entrySet())
          {
              final Circuit circuit = entry.getKey();
              final Xml nodeCircuit = nodeCircuits.createChild(NODE_CIRCUIT);
              nodeCircuit.writeString(ATT_CIRCUIT_TYPE, circuit.getType().name());
              nodeCircuit.writeString(ATT_GROUP_IN, circuit.getIn());
              nodeCircuit.writeString(ATT_GROUP_OUT, circuit.getOut());
  
              exportTiles(nodeCircuit, entry.getValue());
          }
  
          nodeCircuits.save(media);
      }
docs: Export all circuits to an XML file.
  
  @param media The export output (must not be <code>null</code>).
  @param circuits The circuits reference (must not be <code>null</code>).
  @throws LionEngineException If error on export.