@Test
public void testAddEdge() {

    GraphStore graphStore = new GraphStore();
    NodeImpl[] nodes = GraphGenerator.generateNodeList(2);
    graphStore.addAllNodes(Arrays.asList(nodes));
    EdgeImpl edge = new EdgeImpl("0", nodes[0], nodes[1], 0, 1.0, true);
    boolean a = graphStore.addEdge(edge);
    boolean b = graphStore.addEdge(edge);
    Assert.assertTrue(a);
    Assert.assertFalse(b);
    boolean c = graphStore.contains(edge);
    Assert.assertTrue(c);
}