code: public static DirectedGraph<Integer, DefaultEdge> loadGraph(File file) throws IOException, ClassNotFoundException {
  		SerializableDirectedGraph serialGraph;
  		BufferedInputStream fin;
  		ObjectInputStream in;
  		fin = new BufferedInputStream(new FileInputStream(file));
  		in = new ObjectInputStream(fin);
  		serialGraph = (SerializableDirectedGraph) in.readObject();
  		in.close();
  		return serialGraph.getGraph();
  	}
docs: Deserializes a {@link SerializableDirectedGraph} object that is stored in the
  given location. This method returns the {@link DirectedGraph}  object, that is wrapped
  in the {@link SerializableDirectedGraph}.
  
  @param file Must not be {@code null} and valid {@link File}.
  @return The {@link DirectedGraph} object, that is wrapped in the
  {@link SerializableDirectedGraph}.
  @throws IOException Thrown if errors occurred on the IO level.
  @throws ClassNotFoundException Thrown if a class could not be find while deserialization.