External Id causing error

[lucaspg96]

Setting the external id in the Node or Edge constructors and adding them to the graph causes an error.
The following code gives an error:
...

	GraphBounds graph = new GraphImpl(Configuration.USER_HOME + "/graphast/example");

	Edge e;
	NodeImpl v;

	v = new NodeImpl(5l, 1d, 10d, 0);
	graph.addNode(v);

	v = new NodeImpl(1l, 30d, 20d, 2);
	graph.addNode(v);

	v = new NodeImpl(2l, 40d, 20d, 4);
	graph.addNode(v);

	v = new NodeImpl(3l, 50d, 30d, 0);
	graph.addNode(v);

	v = new NodeImpl(4l, 60d, 20d);
	graph.addNode(v);

	
	e = new EdgeImpl(8l,5l, 1l, 1, "Rua AB");
	graph.addEdge(e);

	e = new EdgeImpl(1l,1l, 2l, 3, "Rua BC");
	graph.addEdge(e);

	e = new EdgeImpl(2l,1l, 3l, 2, "Rua BD");
	graph.addEdge(e);

	e = new EdgeImpl(3l, 3l, 2l, 1, "Rua DC");
	graph.addEdge(e);

	e = new EdgeImpl(4l, 2l, 3l, 1, "Rua CD");
	graph.addEdge(e);

	e = new EdgeImpl(5l, 3l, 4l, 5, "Rua DE");
	graph.addEdge(e);

	e = new EdgeImpl(6l, 3l, 5l, 1, "Rua CE");
	graph.addEdge(e);

...