for (final ControlFlowEdge edge : edges) {
final ControlFlowNode from = edge.getSource();
final ControlFlowNode to = edge.getTarget();
output.writeLine("\"%s\":f0 -> \"%s\":f0 [", nodeName(from), nodeName(to));
output.indent();
output.writeLine("label = \"%s\"", edge.getType());
output.unindent();
output.writeLine("];");
}